A spokesperson for the company said it had decided not to release any new titles by Walliams "after careful consideration, and under the leadership of its new CEO".
"HarperCollins takes employee well-being extremely seriously and has processes in place for reporting and investigating concerns," they added.
"To respect the privacy of individuals, we do not comment on internal matters."
In a statement later on Friday, a spokesperson for the comedian and children's author said: "David has never been informed of any allegations raised against him by HarperCollins.
"He was not party to any investigation or given any opportunity to answer questions. David strongly denies that he has behaved inappropriately and is taking legal advice."
It follows a report from The Telegraph that Walliams was dropped after an investigation into allegations of inappropriate behaviour towards young women.
The 54-year-old, who shot to fame with the BBC sketch show Little Britain, is one of the country's best-selling children's writers.
He has written more than 40 books, which have sold more than 60 million copies worldwide and been translated into 55 languages, according to his website.
His first children's book, The Boy in the Dress, was published by HarperCollins in 2008, and he was awarded an OBE in 2017 for services to charity and the arts.
Walliams is also known for Come Fly With Me, another BBC sketch show, and was formerly part of the judging panel for ITV's Britain's Got Talent.
He left the show in 2022 after a recording of him making disparaging comments about contestants was leaked.
The remarks were understood to have been both derogatory and sexually explicit, referring to one contestant as a "c***" and saying of another: "She thinks you want to f*** her, but you don't".
Walliams later released a statement apologising for the "disrespectful comments" and saying they were private conversations that were never meant to be shared.
HarperCollins UK announced in October that it had appointed Kate Elton as its new chief executive, following the departure of former boss Charlie Redmayne.
The ship, called the Qendil, suffered "critical damage" in the attack, according to a member of the SBU, Ukraine's internal security agency.
The tanker is said to be part of Russia's so-called "shadow fleet" - a group of ageing vessels that Kyiv alleges helps Moscow exports large quantities of crude oil despite Western sanctions.
The SBU source said Ukrainian drones hit the ship in neutral waters more than 2,000 kilometres (1,243 miles) from Ukraine.
They said: "Russia used this tanker to circumvent sanctions and earn money that went to the war against Ukraine.
"Therefore, from the point of view of international law and the laws and customs of war, this is an absolutely legitimate target for the SBU.
"The enemy must understand that Ukraine will not stop and will strike it anywhere in the world, wherever it may be."
The vessel was empty at the time of the attack, the Ukrainian source added.
Speaking during a live TV event, Vladimir Putin, the Russian president, claimed the attack would not disrupt supplies, but vowed that Russia would retaliate nonetheless.
He added that Russia regularly responded with "much stronger strikes" against Ukraine.
Putin also warned against any threat to blockade Russia's coastal exclave Kaliningrad, which he said would "just lead to unseen escalation of the conflict" and could trigger a "large-scale international conflict".
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Sky military analyst Michael Clarke said Ukraine's claim about causing significant damage to the ship was "probably true".
He added: "The Ukrainians obviously feel that they can legitimise this sort of operation."
The attack comes after the European Union announced it would provide a €90bn (£79bn) interest-free loan to Ukraine.
Oleksandr Merezhko, the chairman of the foreign affairs committee in the Ukrainian parliament, told Sky News that the money would "tremendously enhance" Kyiv's defensive capabilities.
However, he said the International Monetary Fund estimated that Ukraine needed $137bn to "keep running".
"The aggressor should be punished", Mr Merezhko added, as he argued that frozen Russian assets in Europe should be used to help fund his country's defence.
He vowed that Ukraine would "continue to fight" for the move, adding that it was "a matter of justice".
Police were called to Lime Close in Weston-super-Mare, Somerset, just before 6.10pm on Monday, where Aria Thorpe had suffered a single stab wound.
The child was pronounced dead at the scene.
In a tribute released by Avon and Somerset Police on Friday, the girl's family on her mother's side said: "For those who didn't have the privilege of knowing Aria, she was the most beautiful little soul - happy-go-lucky, full of light, and joy.
"She loved to sing and dance, and she took such pride in dressing up, always wanting to look just like her mummy."
Tom Thorpe, the girl's father, said: "It's hard to put into words how devastating it is, our little Aria, that you're up there with the angels looking over us."
It comes as a 15-year-old boy charged with Aria's murder appeared in court.
Aria was a 'precious girl'
In their statement, Aria's family on her mother's side said her death "has devastated us beyond words".
"Our hearts are broken in a way we never imagined possible," they added.
"As a family, we are holding one another close and doing everything we can to support each other through this unimaginable time."
They said they were "truly touched by the lovely messages we have received", before asking "that our privacy is respected, as we try to come to terms with the terrible loss of our precious girl".
'Wacky ways and outright madness'
Mr Thorpe said: "How sad it's going to be not hearing 'Dad, how long left?' on our long journeys back and forth at weekends.
He then said that Aria was "such a brave, kind-hearted and a beautiful innocent soul", and "always put a smile on people's faces with your wacky ways and just outright madness".
Mr Thorpe added: "Your other little family down here in Portsmouth will forever miss you.
"We'll miss you begging to go outside, even in the pouring rain just to have as much fun as possible in the little time we had at weekends.
"You will be greatly missed, you special little angel. A life gone far too early but I hope a life lived well. We all love you dearly. Goodnight darling."
Teenager in court
Meanwhile, a 15-year-old boy charged with Aria's murder appeared at Bristol Crown Court on Friday, where he was remanded.
The teenager, who cannot be named because of his age, was arrested in the Somerset village of Worle at 6.19pm on Monday.
He is next due in court on 16 March 2026. Appearing via video link from youth detention accommodation, he spoke only to confirm his name.
Judge Peter Blair KC set a provisional trial date for 15 June during the hearing.
The Australian pop star, 57, is the first solo female artist in 12 years to secure the coveted festive spot, after Sam Bailey with Skyscraper in 2013, according to The Official Charts Company.
Minogue has also become the first woman to have number one singles across four different decades.
Her success comes after two consecutive years in which Last Christmas by Wham! was top.
Minogue said it was "hard to put into words" how special it felt to lead the singles chart.
She said: "Being Christmas number one really is the most wonderful gift. I'm so thankful to everyone who's been listening and sharing the love and I'm wishing you all a very Merry Christmas."
Her single - pronounced X-M-A-S - is accompanied by a music video that shows Minogue teaching a dance to a group of children and adults.
It also features a special appearance from Abba's Bjorn Ulvaeus.
Xmas is followed in the singles chart by Last Christmas, with Mariah Carey's All I Want For Christmas Is You at three.
The top five is completed by Brenda Lee's Rockin' Around The Christmas Tree at four and charity single Lullaby by Together For Palestine at number five - this week's highest new entry.
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Kylie has previously topped the singles chart on seven other occasions.
Her other bestselling songs were I Should Be So Lucky (1988), Especially For You (1988), Hand On Your Heart (1989), Tears On My Pillow (1990), Spinning Around (2000), Can't Get You Out Of My Head (2001) and Slow (2003).
Martin Talbot, chief executive of the Official Charts Company, said Minogue may now be placed to challenge Mariah Carey as the "queen of Christmas".
He said: "Congratulations to Kylie - what an amazing achievement by our adopted national treasure."
The last Australian artist to earn the Christmas number one title was Oscar-winning actress Nicole Kidman, who collaborated with Robbie Williams on Somethin' Stupid in 2001.
Michelle Mills and Geraint Berry planned to murder Christopher Mills and make it look like suicide.
They were found guilty of conspiracy to murder after a trial at Swansea Crown Court in October.
A third person, Steven Thomas, was found not guilty of conspiracy to murder but pleaded guilty to a firearms charge.
Police were called on 20 September last year to reports that masked men carrying guns, later found to be Berry and Thomas, had raided a static caravan in Cenarth, Ceredigion.
Despite being badly beaten, Mr Mills was able to fight them off and they fled.
Michelle Mills, 46, called 999 to say her husband had a head injury and claimed she did not know the armed men who broke in.
Armed officers and a dog unit responded, and a police helicopter soon spotted Berry, 46, and Thomas, 47, hiding in undergrowth.
While searching Berry and Thomas, officers found gas masks and a typed suicide note addressed to Mills purporting to have been written by her husband.
Police quickly established that Mills, of Llangennech in Carmarthenshire, was linked to the plot.
Digital evidence revealed she and Berry - a former Royal Marine - had been in a secret relationship for around three months and had discussed ways to kill Mr Mills.
These included killing him with sleeping tablets, suffocating him in his sleep and poisoning him with antifreeze.
Berry also looked into how to make his victim's Mini explode on start up.
Police said when Berry told Mills he was meeting with some "boys" to plan "what they are going to do with him", she responded: "Yes, lovely, thank you."
Gas masks were 'to set up a fake suicide'
Detective Inspector Sam Gregory said: "Berry and Mills had previously discussed using gas to kill Mr Mills, while making it look like he had taken his own life.
"Berry had asked Mills where the boiler was, and he and Thomas carried gas masks that would have protected themselves while Mr Mills suffocated.
"No explanation has been given by any of the three defendants for the fake suicide note or the gas masks in the rucksack.
"What's clear is that these were not being used to frighten Mr Mills - they were there to set up a fake suicide."
DI Gregory said the victim had no idea his wife of 10 years wanted him dead and believed they had a happy marriage.
'Your intention was to kill'
Judge Mr Justice Nicklin KC said the pair had not shown any remorse and they were only concerned with not getting caught.
"You devised the plan and led its execution," he told Berry.
"You recruited Steven Thomas to assist you and while intoxicated, you equipped yourself with items that demonstrated your intention to kill Mr Mills and make it appear to be a suicide.
"However incompetent the plan was and how unlikely it was to be achieved, your intention was to kill."
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The judge told Michelle Mills she had encouraged her lover.
He said: "The evidence strongly suggests in the weeks leading up to the incident, you cultivated and exploited Geraint Berry's animosity towards your husband and encouraged him to find a way to get rid of your husband, not in fantasy but reality."
The judge also praised Mr Mills' "remarkable fortitude and courage" in fighting off the pair.
Steven Thomas was sentenced to 12 months but will be released immediately due to time served on remand.