The Sun's decision to publish pictures of Prince Harry naked, in defiance of legal warnings from St James's Palace, could prompt an investigation by the Press Complaints Commission (PCC).
The watchdog said it had received more than 850 complaints about the images, published in yesterday's paper despite warnings from royal aides that they could be an invasion of the Prince's privacy. The PCC will ask St James's Palace if it wishes to make a formal complaint after its warning that use of the pictures could constitute a breach of the Editor's Code.
"We've received those complaints and will now follow due process and consider them," a spokesman said.
The watchdog can consider third-party complaints but would normally expect the individual concerned to seek redress. A Palace spokesman said: "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."
The decision by the News International-owned paper to break ranks and publish the images, taken at a party in Prince Harry's Las Vegas hotel suite and sold to the TMZ gossip website, prompted a mixed reaction.
Despite speculation that proprietor Rupert Murdoch had personally instructed The Sun to run the pictures, insiders said Dominic Mohan, the editor, had taken the decision.
Mr Murdoch's daughter, Elisabeth, publicly backed The Sun's decision, saying it would be "very sad if we lived in a world where you can't publish that". She added: "I went online and checked out the pictures. I think he's cute. If newspapers can't participate in that I think it asks questions about where print and online [meet]."
The managing editor of The Sun, David Dinsmore, said it would have been "perverse" not to publish the pictures, for which the paper paid £10,000. They were "now in the public domain in every country in the world", he said. The paper said its readers had a right to see the pictures and the freedom of the press was being tested.
Industry experts warned that the move could drive Lord Justice Leveson, currently compiling recommendations for a new press regulatory regime, to opt for a statutory system.
Mark Stephens, the leading media lawyer, said The Sun had "prevented Leveson from going the self-regulation route". He added: "They will be the pariahs of Fleet Street for this."
But Stig Abell, a former director of the PCC, said The Sun had taken an "informed decision". He said: "They concluded that a tipping point had been reached. You can't publish something just because it's already on the internet but the question was 'is this information even private?' when it's been shared by 100 million people."