Princess Diana
Princess Diana arrives at the Royal Geographical Society in London for a speech on the dangers of landmines throughout the world June 12, 1997. Reuters/Ian Waldie

Princess Diana leaked the contents of a royal phone book to now-defunct British tabloid, News of the World, in order to "take on" her husband Prince Charles, the paper's former royal editor, Clive Goodman, reportedly told the court Thursday, during the ongoing phone-hacking trial, which led to the paper's closure in 2011.

Goodman said that the confidential directory, which contained numbers of high-ranking officials and senior members of Britain’s royal household, was delivered to the newspaper’s office in 1992, adding that, after sending the directory, Diana called him to confirm he had received it.

"She was looking for an ally to take [Prince Charles] on - to show there were forces that would rage against him," Goodman reportedly told the jury.

Goodman, who was jailed in 2007 for illegally accessing the voicemails of mobile phones belonging to royal aides, is on trial for making illegal payments to police officers to obtain the royal telephone directory. Police had reportedly seized 15 such directories from Goodman’s home when he was arrested in 2006. Goodman has denied taking the directories from officials or paying for them.

Goodman reportedly told the Old Bailey about Diana: “She was going through a very, very difficult time,” adding: “She told me she wanted me to see the scale of her husband's staff and household, compared with others. She felt she was being swamped by people close to his household.”

Diana had separated from Charles in December 1992 and the couple divorced in 1996. Diana was killed in a car crash in Paris the following year.

Goodman reportedly told the jury that he had been "well thought of" as the assistant editor of the tabloid, specializing in royal coverage, until Andy Coulson, who later became Prime Minister David Cameron's media chief, took over as the tabloid's editor in January 2003, with whom he got along well initially.

"Then my relationship with him changed. He became more aggressive, more combative, more bullying." The culture of the paper under Coulson had been "extraordinarily competitive, very fast, quite bullying and menacing," Goodman said.

Coulson is accused of authorizing the hacking of phones and the alleged illegal payments made by Goodman. And, during the course of the trial, four other former News of the World journalists, including three senior editors, have reportedly admitted to conspiring to hacking phones during Coulson's editorship.

Goodman, 56, has denied committing misconduct in a public office, while Coulson has denied all charges against him.