Prince Harry settled on Wednesday his long-running lawsuit against Rupert Murdoch's UK tabloid publisher, which agreed to pay him "substantial damages" after admitting intruding into his private life, including by hacking his phone.

Murdoch's News Group Newspapers (NGN) issued a wide-ranging apology and admission of wrongdoing, in what Harry's lawyer David Sherborne called "a monumental victory" that underlined the need for further probes.

The publisher apologised to him for the impact of the "serious intrusion" into the private life of his late mother Diana, Princess of Wales, particularly when he was younger.

The settlement won by King Charles's youngest son concludes a years-long legal battle over claims of unlawful practices by two of Murdoch's newspapers -- The Sun and now-shuttered News of the World.

It also avoids a High Court trial in the public spotlight, which had been due to begin on Tuesday and last up to eight weeks.

"NGN offers a full and unequivocal apology... for the serious intrusion by The Sun between 1996 and 2011 into his private life," an NGN statement said.

That included the unlawful activities of private investigators working for the tabloid, it said.

It also apologised for the "phone hacking, surveillance and misuse of private information" by journalists and private investigators working for the News of the World.

Acknowledging the damage inflicted on Harry's "relationships, friendships and family", it said it would pay him "substantial damages". (AFP)