Misconduct in public office refers to "serious wilful abuse or neglect" of powers relating to the role in public office, according to the Crown Prosecution Service (CPS).
It states there must be a direct link between the misconduct and an abuse of those powers or responsibilities without reasonable excuse or justification.
Andrew has consistently denied any wrongdoing.
Joshua Rozenberg, a legal commentator, told Sky News that it is an "unusual" offence "because it's one created by the judges, laid down by the courts over many years" instead of statute.
He said: "For that reason, there isn't actually a maximum penalty at all. It's life imprisonment because parliament has never actually set a maximum.
"What it actually boils down to is whether the police have evidence that Andrew Mountbatten-Windsor wilfully misconducted himself as a trade envoy to such a degree as to amount to an abuse of the public's trust in him."
The CPS website states there is no simple definition of a 'public officer', meaning each case must be assessed individually.
This includes taking into account the nature of the role, the duties carried out, and the level of public trust involved.
The British Monarchy acts as a public institution in a non-political sense, with members of the Royal Family expected to support the monarch while also carrying out work in the areas of public and charitable service in their own right.
Due to the "complicated" nature of the offence, Mr Rozenberg said the government is trying to replace it with a new law, the Public Office (Accountability) Bill, which is currently going through parliament.
Part of the bill covers misconduct in public office, stating that a person commits an offence if they use "their office to obtain a benefit, whether for themselves or somebody else, or to cause somebody else to suffer a detriment".
How long can police hold Andrew?
It remains unknown where Andrew is being held, or what time he was arrested, but suspects are typically held for 24 hours and are then either charged or released pending further investigation.
Technically the longest the former prince can be held by police is 96 hours, however this would require several extensions from senior police officers and a Magistrates' Court.
For an extension to be applied, the court must be satisfied that the detention is necessary to secure/preserve evidence, the investigation is being conducted diligently, and the offence is serious.
Mr Rozenberg told Sky News that he thought it was unlikely Andrew would be held overnight, if he is being questioned at a police station.
"That's perhaps one reason for arresting him first thing in the morning," he said.
"But again, if he doesn't have anything to say, and I'd be surprised if he wants to say anything to the police, then perhaps the interview isn't going to take very long."
The detention of the King's brother is "about as critical" an event "as the institution could have to face", Alastair Bruce said.
"For the King, it must be awful to face this... he is the person in whose name ultimately police constables do their work, and now his brother is a subject of a judicial process," he explained.
"I think it must be ghastly for the King and for all members of the Royal Family to watch this take place."
Andrew arrest latest: King says 'law must take its course'
The former prince was arrested on his 66th birthday after footage showed unmarked police cars arriving at Wood Farm on the Sandringham Estate in Norfolk, where he has been living after leaving his previous home, Royal Lodge in Windsor.
Thames Valley Police confirmed the arrest, which came after allegations made against the former duke following the release of millions of pages of files related to paedophile financier Jeffrey Epstein.
The force previously said it was reviewing allegations that a woman was trafficked to the UK by Epstein to have a sexual encounter with Andrew, as well as claims he shared sensitive information with the US sex offender while serving as the UK's trade envoy.
Andrew has always vigorously denied any allegations of wrongdoing in connection with Epstein.
Bruce said the only other time a sibling of a serving monarch had been arrested was when Elizabeth Tudor was detained in 1554 over her supposed involvement in the Wyatt plot - a rebellion that attempted to prevent her sister Queen Mary's marriage to Philip of Spain.
"I think that gives you a sense of how distant it is to the concept of what monarchy is about and how it should serve," he added.
"The nation is not expecting this kind of thing from someone who was once the son of a sovereign - and the brother of a sovereign."
'Arrogant' Andrew facing 'his worst nightmare'
Similarly, royal commentator Jennie Bond said Andrew's arrest was "probably the worst nightmare for the palace and for the King".
Asked what the former duke's response would be to the arrest, she said: "You would think he now is finding himself face to face with the reality of the fact that he is no longer in the privileged position he was in before.
"Yes, he is arrogant. Now he is being ordered, one assumes, to do whatever the police are saying he must do.
"It's something he would never have experienced in his life, and it would be his worst nightmare as well, I think."
Foreign Secretary Yvette Cooper has condemned their sentence as "completely appalling and totally unjustifiable".
"We will pursue this case relentlessly with the Iranian government until we see Craig and Lindsay Foreman safely returned to the UK and reunited with their family," she said.
Joe Bennett, Lindsay Foreman's son, told Sky News' Jason Farrell he had spoken with the couple since their sentencing, describing how they reacted to the news with a "kind of mass panic".
He said the prison sentence left him with a "pit in the stomach" describing how "I felt sick, [I] didn't sleep".
The couple were arrested in January 2025 while travelling through the country on an around-the-world motorcycle journey and detained on charges of espionage.
The Foremans, from East Sussex, who are being held in Tehran's Evin prison, deny the allegations.
The couple's family says the sentence places the case "in line with the most severe politically motivated detentions of UK nationals in Iran".
Mr Bennett said that the couple has been "sentenced to 10 years following a trial that lasted just three hours and in which they were not allowed to present a defence".
"They have consistently denied the allegations. We have seen no evidence to support the charge of espionage," he added.
The sentence follows a court appearance on 27 October 2025 before Judge Abolghasem Salavati at Branch 15 of the Islamic Revolutionary Court in Tehran.
Judge Salavati has previously been sanctioned by the UK, US and EU in connection with human rights violations and the conduct of trials criticised internationally for lack of due process.
Ahead of his sentencing, Mr Foreman described being held in an "eight-foot cell with a hole in the floor and a sink" and described the effects of 57 days in solitary confinement, saying: "Emotionally and physically, it broke me to pieces".
He said once a month meetings with his wife are what sustain him.
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Mr Bennett said the couple had "already spent more than thirteen months in detention". "We are deeply concerned about their welfare and about the lack of transparency in the judicial process," he added.
He told Jason Farrell that the couple's family had received a call straight away from Foreign Office minister Hamish Falconer who was "quite forceful in the fact that he was going to pick it up with his counterparts".
Mr Bennett also welcomed Ms Cooper's statement, saying he had already noticed a "different tone... from the government and that's only been within 24 hours".
"For the first time, there's a sentence that the government can now act on, which is what they've been asking for for the last 14 months," he added.
The Foreign Office is currently warning people not to travel to Iran, because of "the significant risk of arrest questioning or detention". "The UK government will not be able to help you if you get into difficulty in Iran," it has cautioned.
Iran has arrested dozens of foreign visitors and dual nationals in recent years, mostly on espionage and security-related charges.
Human rights groups and some Western countries have accused Iran of trying to win concessions from other nations through arrests on trumped up charges.
British-Iranian dual nationals like Nazanin Zaghari-Ratcliffe and Anoosheh Ashoori are among those who have spent years behind bars in Iran before diplomatic negotiations helped secure their release.
The sentencing of the Foremans comes amid heightened tensions in the region following a deadly crackdown on a wave of demonstrations in Iran.
Donald Trump last month urged Iranian protesters - thousands of whom have been killed by the regime's forces - to keep demonstrating and promised that "help is on the way".
A powerful US military force continues to assemble within striking distance of Iran.
Ashley Warren, 41, has been found guilty of owning an XL bully dog called Bear that mauled Esther Martin in Jaywick, Essex, on 3 February 2024.
But a jury cleared him of being in charge of another XL bully called Beauty, which also injured Ms Martin.
The medical cause of her death was recorded as "dog bite wounds to the upper right limb".
A jury heard Ms Martin, who was 5ft 3in tall, had limited mobility following a hip replacement and had suffered "dozens and dozens" of injuries in the attack.
Warren, now of Addlestone, Surrey, had left her with the two dogs, named Beauty and Bear, and eight puppies of the same breed, at his home in Hillman Avenue.
The amateur rapper had asked Ms Martin to mind the animals so he could travel to London to film a music video.
Warren had pleaded not guilty to being the owner of a dog named Bear which caused injury resulting in death while dangerously out of control in a private place.
He also denied being a person in charge of a dog named Beauty which caused injury resulting in death while dangerously out of control in a private place.
During the trial, at Chelmsford Crown Court, he said the XL bullies were "loving dogs" and were not "raised to attack or bite".
The case was the first of its kind since new laws on owning XL bullies came into effect at the start of 2024, Essex Police said at the time.
An inquest hearing was previously told Ms Martin was found unresponsive and had sustained "unsurvivable" dog bite wounds.
Warren was also found guilty of one count of possessing a knife at Clacton railway station on 3 February 2024.
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Kevin Weetman, 34, was sentenced to a minimum of 25 years alongside two others who were also imprisoned over the deaths of Sheila Jackson, 83, and Eric Greener, 77.
Sheila's son, George Jackson, who also lived at the house, was said to have been the intended victim in a row over drugs.
One of Weetman's sellers, Kylie Maynard, 37, was jailed for 23 years; and Lee Owens, 46, was handed 13 years and six months inside after all three were convicted of manslaughter.
The couple were killed in an arson attack at their terraced home in St Helens, Merseyside, in July 2025.
Liverpool Crown Court heard Weetman planned the attack on Ms Jackson's son after he refused to sell drugs for him.
As he was sent down after sentence by the judge on Thursday, a family member in the public gallery shouted: "You're not laughing now, Weetman."
The defendant replied: "I'm always laughing."
Weetman, Maynard and Owens were cleared of murder on Tuesday following a five-week trial.
Both Owens and Weetman were seen smiling and laughing together in court as the verdict was delivered, while Maynard showed no visible reaction.
Owens, who had admitted manslaughter, claimed he intended to only damage the house.
Both Weetman and Maynard admitted conspiring together to supply cocaine between November 2024 and September 2025, but had denied having anything to do with the fire.
Sentencing them on Thursday, Mr Justice Jay said: "This is an appalling case involving the untimely deaths of two innocent elderly people."
Weetman was described by the judge as "a man with an entirely warped moral code".
His criminal record dated back to a conviction for battery when he was 12 and included leaving a police officer with brain damage after he ran over him on his scooter when he was 15 and under an anti-social behaviour order.
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Mr Justice Jay said a letter sent to him by Weetman ahead of the sentence was "too late".
He said: "He can't come along now having lied to the jury in a systematic fashion and denied any involvement when it was, frankly, as plain as a pikestaff that he masterminded all of this.
"I'm grateful for the letter but it is too late."
Peter Wright KC, defending Weetman, said the motivation for the attack was more likely to be the "instilling of terror" than a murderous intent.
In a statement read to the court by Alex Langhorn, prosecuting, Ms Jackson's daughter Sharon Jackson said: "Mum and Eric were our world. They were our life.
"You took their precious lives away from them. You did that. You didn't care who was in that house."
After the sentencing, the couple's family said their deaths were the result of an "unforgivable, unprovoked, premeditated attack".
The trial heard Owens and another man, Paul Smith, 40, who has since died, travelled from Liverpool to St Helens to start the blaze just after 12.30am on 15 July last year.
Mr Jackson, the intended target, was out at the time and returned to find his mother being carried from the burning property by firefighters.
Mr Greener was also rescued from the fire, but both died in hospital from burns and smoke inhalation.
Owens and Smith were allegedly "put up" to carry out the attack by Weetman, with Maynard's assistance, after they attempted to trick Mr Jackson into working as a drug dealer.
The jury was told Mr Jackson had been presented with half an ounce of cocaine as a gift by Weetman after he helped Maynard when her drugs were robbed.
But, after Mr Jackson twice declined to work for Weetman the drug dealer started to ask for his "dough" and resolved to take action to "prevent a loss of face", the prosecution alleged.
Weetman told the jury: "I weren't committing murders. I'm a drug dealer."
The court heard he played a "leading role" in a drugs line that made about £8,000 a week, while Maynard was his "trusted lieutenant".