Prince Harry is to sue the publishers of British tabloids The Sun and The Mirror over allegations of phone hacking, according to his office and court documents.
"Claims have been filed on behalf of The Duke of Sussex at the High Court regarding the illegal interception of voicemail messages," a spokeswoman for the Duke of Sussex said.
No further details were given but it is thought to related to historic phone hacking.
A spokeswoman for Rupert Murdoch's News Group Newspapers, publisher of The Sun, confirmed that a claim had been issued.
Documents lodged at the High Court show the defendants as Newsgroup Newspapers Limited and MGN [Mirror Group Newspapers] Limited.
It comes after a furious Harry issued a statement on Tuesday blasting the British media over the treatment of his wife, Meghan Markle.
He described it as a "relentless propaganda" campaign.
"I have been a silent witness to her private suffering for too long. To stand back and do nothing would be contrary to everything we believe in," the prince said.
"There comes a point when the only thing to do is to stand up to this behaviour, because it destroys people and destroys lives. Put simply, it is bullying, which scares and silences people."