Prince Harry mentions ex-girlfriend Chelsy Davy in UK court

Prince Harry on Wednesday blasted the publisher of two UK tabloid newspapers for "terrifying" coverage of his relationship with ex-girlfriend Chelsy Davy that felt like "full blown stalking", as he gave evidence at London's High Court.

On the third day of the highly anticipated nine-week trial, Harry began testifying against Associated Newspapers Ltd (ANL), the publisher of the Daily Mail and The Mail, which he and six others accuse of unlawful information gathering against them.

The newspaper group strenuously denies his claims.

Harry insisted in a witness statement to the court that the trial was not "not just about me" but was also in the wider public interest.

The suspicion that people close to him were leaking stories to the press created an atmosphere of "distrust", he said, that led to the breakdown of his relationship with another girlfriend, Natalie Pinkham.

"It led to me not speaking to her for years," he stated. "...but I now believe that it (the articles) will have come from listening in to our communications, voicemail interception and/or blagging (impersonation)."

Referring to his romance with Davy, Harry said in his statement the coverage by two journalists in particular was oppressive.

"They turned up everywhere. It felt like full blown stalking and constant surveillance... This sort of intrusion was terrifying for Chelsy," he said.

"It made her feel like she was being hunted and the press had caught her and it was terrifying for me too because there was nothing I could do to stop it," he added.

The case has been brought by Harry alongside six other high-profile figures, including pop icon Elton John and his husband David Furnish.

It is the prince's last active legal case in his long-running crusade against the British media.

"There is obviously a personal element to bringing this claim, motivated by truth, justice and accountability, but it is not just about me," he said in the statement unveiled as he entered the witness box.

"There is also a social element concerning all the thousands of people whose lives were invaded because of greed," the prince said.