The Duchess of Sussex was “arguably” behind a “nasty and untrue” article about her father published in People magazine in the US, which he had the right to publicly address, a court in London has heard. On the closing day of a three-day appeal hearing brought by the publisher of the Mail on Sunday, lawyers representing Associated Newspapers Ltd (ANL) argued that Meghan had written a five-page letter to her father, Thomas Markle, “with potential public consumption in mind” and there was a public interest in correcting assertions made in the 2019 article. Andrew Caldecott QC, representing ANL, said the People article referred to the letter Meghan had written to her father and had given it a “wholly misleading gloss”. He said the People article suggested that Meghan had been “always dutiful … supporting him throughout with incredible generosity” and he had “cold-shouldered her at the wedding, in one of the most important parts of her life”. Markle had been accused of giving a “cynical and self-interested response ignoring her pleas for reconciliation in a loving letter”. But Caldecott argued Meghan’s letter to her father was “not a loving letter, not a generous letter”, containing allegations that were “demonstrably false”. Caldecott said it was perfectly reasonable that Markle assumed his daughter was behind the article and there was an urgency to reply to the claims, as he had been “left in a lonely place” and the magazine had 40m readers a week. “Either we believe in freedom of expression or we don’t,” he said. “Thomas Markle has been royally attacked in the People magazine … and this is his reply.” In February, Meghan successfully sued ANL, the publisher of the Mail on Sunday and the MailOnline website, for breach of privacy and copyright, over five articles that published parts of the “personal and private” handwritten letter sent to her father. A high court judge ruled in her favour, saying publication of the letter to Thomas Markle was “manifestly excessive and hence unlawful” and could be dealt with by summary judgment without need for a trial. ANL challenged that ruling this week, arguing the case should go to a trial. During the hearing on Wednesday, Meghan apologised for failing to remember authorising a senior aide to brief the authors of her and Harry’s unofficial biography. In a statement in the court of appeal, Meghan said she could not remember emails between her and her then press secretary, Jason Knauf, about the unauthorised book Finding Freedom by Omid Scobie and Carolyn Durand. She said: “When I approved the passage … I did not have the benefit of seeing these emails and I apologise to the court for the fact that I had not remembered these exchanges at the time. I had absolutely no wish or intention to mislead the defendant or the court.” Lawyers for the duchess said she had provided “background information” to the authors of her and Harry’s unofficial biography, but kept the contents of a contested letter to her father secret. On Thursday, Justin Rushbrooke QC, representing the duchess, said that it made “no sense” to argue that the duchess wanted to share the contents of her letter, when the “background information” she allowed him to share did not contain details of the letter. “She had every opportunity. This was the perfect opportunity if you wanted to put it into the public domain,” he argued. Further documents were released that revealed that Knauf, who is due to stand down from his current role as the chief executive of the Royal Foundation at the end of the year, had “regretted” not giving evidence after Meghan won her legal battle against ANL. In a witness statement, Keith Mathieson, a solicitor for ANL, said he believed Knauf’s evidence was “honest and credible” and could not have been obtained earlier. Mathieson called Knauf “a central figure in the events he describes” and said his witness statement was measured. He added: “Given the high-profile nature of this litigation and the likelihood of his evidence (if admitted) being widely reported, as well as the position he holds, it is hardly conceivable that he would say anything he did not believe to be true and I know of nothing in his evidence which is subject to any reasonable challenge.” The case was heard by Sir Geoffrey Vos, Dame Victoria Sharp and Lord Justice Bean, who will publish their judgment at a later date.