A key witness in a lawsuit brought by Prince Harry and other high-profile ‌figures against the Daily Mail has told London’s High Court the claimants were conned, and denied signing a damning statement.

Harry, the younger son of the King, and six others including singer Sir Elton John have accused Associated Newspapers’ tabloids of involvement in widespread unlawful ‌information gathering including phone-hacking dating back 30 years.

Associated, which also publishes the Mail on Sunday, has denied any wrongdoing.

The trial has already heard evidence from Harry and the other claimants, as well as senior current and former journalists and staff at Associated.

On Monday, private investigator Gavin Burrows, whose testimony could decide the outcome, said the lawsuit “was based on a pack of lies”.

In August 2021, the claimants’ ‌lawyers say Burrows signed ‌a witness statement in ⁠which he stated he had “targeted hundreds, possibly thousands of people” for Associated, from tapping landlines and hacking ​voicemails to obtaining information by deception.

Those allegations help form a substantial part of the claimants’ case.

Burrows later told Associated’s legal team he had never made this statement and that his signature had been faked. He told the court he had first heard about the allegations attributed to him by reading a newspaper report.

“This statement has nothing to do with me,” Burrows – who gave evidence from an undisclosed overseas location as he says he and his family have ⁠received threats – told the court by videolink.

“You have got to explain to your ‌claimants how ​you have been conned,” he said during testy exchanges with their lawyer David Sherborne who was given permission to treat his own witness as “hostile”.

“This ​thing is based ‌on a pack of lies.”

Associated has cast the whole case as manufactured and funded by opponents of the press such as the ​late motor-racing boss and privacy campaigner Max Mosley, and that a “research team” assisting the claimants’ lawyers had paid witnesses to provide evidence.

Sherborne accused Burrows of lying, suggesting he decided to change his evidence only after he fell out with one of the research ​team, ​Graham Johnson.

Johnson is a journalist who was convicted of phone-hacking and ​now writes about tabloids’ unlawful activities. He has previously told the court that ‌Burrows agreed to a book deal and to help with documentaries, for which he had been paid £75,000 ($A142,971), and that their relationship fell apart in early 2022.

Burrows said he had no knowledge that he would be used in the Associated litigation until January 2023 when he became “absolutely furious” that his name was being linked.

He said he approached the publisher because he thought one of the claimants, racism campaigner Doreen Lawrence, ​was being conned.

“The whole thing is a thing of fiction,” he said.

He told the court he had never worked for or ​been paid by Associated.

Burrows is the ⁠last witness at the trial, which began in January, with closing submissions due later this month.

-AAP