What's Prince Harry's case against the Daily Mail's publisher?

Prince Harry, British pop star Elton John and others are suing Associated Newspapers, which publishes Daily Mail newspaper, for unlawful information gathering in a trial which started on Monday.

The claimants' lawyers allege that commissioning private investigators who unlawfully gathered private information was part of the Associated Newspapers' "modus operandi".

"There can be little doubt that journalists and executives across the Mail titles engaged in or were complicit in the culture of unlawful information gathering that wrecked the lives of so many," they argued in court documents.

Associated spent more than 3 million pounds ($4.02 million) between 1991 and 2011 on private investigators, the claimants say. 

Some of the investigators have been found to have carried out unlawful acts in litigation against other media groups.

The claimants also allege that Associated "deliberately concealed" wrongdoing and withheld evidence from a public inquiry into the standards and practices of the British press, which took place between 2011-12.

Associated's lawyers say, however, that the allegation that unlawful information gathering was widespread at the publisher's titles is "simply untrue".

Harry's claim centres on 14 articles, including two featuring details of private conversations with his brother William about their late mother Diana, published by Associated's titles between 2001 and 2013.

The publication of the information, which Harry's lawyers say had no legitimate source, had "a profoundly negative impact on his personal relationships ... and private life".

Harry's former nanny asking him to be godfather to her child was published, despite the fact even Harry's father Charles was unaware, his lawyers said.

The royal says in his witness statement, quoted in documents made public on Monday, that it was "disturbing to feel that my every move, thought or feeling was being tracked and monitored just for the Mail to make money out of it".

"Associated strongly denies that there was any voicemail interception or other (unlawful information gathering) directed at the Duke of Sussex (Prince Harry)," the publisher's lawyers argue.

The previous "strenuous" denials of unlawful activity by Paul Dacre, the Daily Mail's longstanding former editor, at a public inquiry over a decade ago are heavily relied on by the claimants as to why they did not take action sooner.

Victoria Newton, editor of Rupert Murdoch's newspaper the Sun, is alleged to have been "a habitual user of private investigators who engaged in unlawful acts" as a Mail reporter in the 2000s. She is not being called to give evidence.

Associated's lawyers say the articles written by Newton were "legitimately sourced".

Doreen Lawrence, whose son Stephen was killed in a racist murder in south London in 1993, said she feels "profoundly betrayed" by the Mail titles, which were a significant supporter of her family's campaign for justice.

"I am a victim all over again, but by people who I thought were my allies and friends," Lawrence said in a witness statement, quoted in court documents.

Associated said in a statement in 2023, during the first hearing in the litigation, that it was "profoundly saddened that (Lawrence) has been persuaded to bring this case".

Actor Sadie Frost found out she was pregnant in late 2003 and doctors said it was an ectopic pregnancy, when a fertilised egg implants outside the uterus, usually in the fallopian tube. The pregnancy cannot be saved and it can cause serious health problems.

She terminated the pregnancy and "did not tell her sisters, or even her own mother ... such was her intent on ensuring no one at all found out", Frost's lawyers said in court documents.

They allege that a Mail on Sunday reporter found out about the pregnancy, the termination and who the father was from "blagging" information from a hospital.

No story was ever published but Frost's lawyers say that a draft article contains intensely private information which was clearly unlawfully obtained.

Associated says the information came from a "freelance journalist with confidential sources close" to both Frost and her then estranged husband, actor Jude Law.