Clive Goodman confirmed during a recent trial that it was Princess Diana who was responsible for leaking a royal phone directory to the UK tabloid News of the World, according to reports.
Goodman claimed that the late princess sent him the information in the mail in 1992 - the same year Diana separated from her husband, Prince Charles.
"She was going through a very, very difficult time. She told me she wanted me to see the scale of her husband's staff and household, compared with others," Goodman told London's Old Bailey during the trial.
"She felt she was being swamped by people close to his household. She was looking for an ally to take him on - to show there were forces that would rage against him," he said.
Goodman, 56, is currently on trial for two counts of conspiring to commit misconduct in a public office. He was also charged for allegedly paying public officials for a royal phone directory - something he immediately denied.
In 2007, Goodman was sent to prison for hacking into the phones of members of the royal household, including Glenn Mulcaire, a public investigator.
Goodman also told the court that he used "Green Books" and internal telephone directories containing the contact numbers of the royal staff and senior members of the household for his stories.
He claimed he did not pay for the "Green Books," when asked by his defending lawyer while in court. Instead, he said that it was given to him directly by the late princess.
"That arrived at my office in Wapping with my name on it. She had a good relationship with several journalists - Richard Kay at the Daily Mail, Martin Bashir of Panorama," he explained.
Diana was killed in a car crash in Paris in 1997.
