The latest hearing in the Duchess of Sussex’s legal action against The Mail On Sunday will be heard by the High Court, following her “comprehensive win” last month.

Meghan, 39, sued Associated Newspapers Limited (ANL) – the publisher of The Mail On Sunday and MailOnline – over a series of articles which reproduced parts of a handwritten letter sent to her estranged father, 76-year-old Thomas Markle, in August 2018.

She claimed the five articles published in February 2019 involved a misuse of her private information, breached her copyright and breached the Data Protection Act.

In a ruling in February, Mr Justice Warby granted Meghan summary judgment in relation to her privacy claim, meaning she won that claim without having to go to trial.

The judge also granted summary judgment in relation to most of the duchess’ copyright claim, saying The Mail On Sunday’s articles “copied a large and important proportion of the work’s original literary content”.

At a remote hearing on Tuesday, the judge – now Lord Justice Warby, following his recent promotion to the Court of Appeal – will hear further argument on “the next steps” in the legal action.

The hearing is expected to deal with applications for ANL to pay Meghan’s legal costs of bringing the case as well as the remaining parts of her claim, including unresolved issues relating to copyright.

Last month, the judge ruled that the publication of Meghan’s letter to her father was “manifestly excessive and hence unlawful”.

He said: “It was, in short, a personal and private letter.

“The majority of what was published was about the claimant’s own behaviour, her feelings of anguish about her father’s behaviour, as she saw it, and the resulting rift between them.

“These are inherently private and personal matters.”

He said “the only tenable justification for any such interference was to correct some inaccuracies about the letter”, contained in an article in People magazine, published just days before ANL’s five articles, which featured an interview with five friends of Meghan.

But the judge added: “The inescapable conclusion is that, save to the very limited extent I have identified, the disclosures made were not a necessary or proportionate means of serving that purpose.

“For the most part they did not serve that purpose at all.

“Taken as a whole the disclosures were manifestly excessive and hence unlawful.”

He also said ANL’s arguments on ownership of the copyright of the letter “seem to me to occupy the shadowland between improbability and unreality”.

However, the judge said the issue of whether Meghan was “the sole author” – or whether Jason Knauf, formerly communications secretary to the Duke and Duchess of Sussex, was a “co-author” – should be determined at a trial, despite being one “of minor significance in the overall context”.

Meghan’s data protection claim was not considered at the summary judgment hearing earlier this year and is still outstanding.

In a statement after the ruling in February, the duchess said: “After two long years of pursuing litigation, I am grateful to the courts for holding Associated Newspapers and The Mail On Sunday to account for their illegal and dehumanising practices.”

She added: “The world needs reliable, fact-checked, high-quality news.

“What The Mail On Sunday and its partner publications do is the opposite.

“We all lose when misinformation sells more than truth, when moral exploitation sells more than decency, and when companies create their business model to profit from people’s pain.

“But, for today, with this comprehensive win on both privacy and copyright, we have all won.”

A spokesperson for ANL said they were “very surprised” by the ruling and would “decide in due course whether to lodge an appeal”.

The hearing on Tuesday is due to begin at 10.30am.