The Sun, Rupert Murdoch's popular British tabloid, on Friday published nude photographs of Prince Harry despite being asked not to by the royal family.
A picture of the nude Prince appeared on the front of Friday's edition next to the headline "Heir it is".
British newspapers had previously refrained from running the grainy snaps showing the third in line to the throne cavorting naked with friends in a Las Vegas hotel suite, but the top-selling tabloid said its readers had a "right to see them".
"The Sun is publishing the naked Prince Harry party pictures our readers have been prevented from seeing in print," it said in a statement.
"He often sails close to the wind for a royal -- but he's 27, single and a soldier.
"We like him. We are publishing the photos because we think Sun readers have a right to see them. The reasons for that go beyond this one story," it added.
Royal officials contacted the Press Complaints Commission (PCC) media watchdog to try and prevent publication, arguing it would breach his privacy, but the pictures have been widely seen on the Internet.
A St James's Palace spokesman said later: "We have made our views on Prince Harry's privacy known. Newspapers regulate themselves, so the publication of the photographs is ultimately a decision for editors to make."
Sun managing editor David Dinsmore said the paper had "thought long and hard" about whether to run the shots.
"We are not against him (Harry) letting his hair down once in a while. For us this is about the freedom of the press.
"This is about the ludicrous situation where a picture can be seen by hundreds of millions of people around the world on the Internet, but can't be seen in the nation's favourite paper read by eight million people every day.
"This is about our readers getting involved in discussion with the man who's third in line to the throne, it's as simple as that."
Industry figures put the media's hitherto reluctance to publish down to the fallout from last year's phone-hacking scandal at Rupert Murdoch's News of the World, which sparked the judge-led Leveson Inquiry into press ethics.
But some newspapers complained that they had been gagged by the royal family.
The Daily Mail said lawyers for Harry's father Prince Charles had threatened legal action against British papers which published the photographs, even though they were freely available online, making "a mockery of our privacy laws".