Publishing photographs of Prince William strolling down to his local pub has landed a Sunday newspaper in hot water with St James's Palace.
William is studying the history of art
The Palace is consulting the Press Complaints
Commission (PCC) about the pictures, which appear under the headline Free Willy in the News of the World.
In its editorial, the paper says the "charming" shots of William wearing jeans, a fleece jacket, trainers and a baseball cap "say more than a thousand posed photocalls could ever do".
But a Palace spokeswoman said: "We take a dim view of the publication of these pictures."
Newspapers had agreed to leave the prince alone during his time at St Andrews University in Fife, so he could enjoy a reasonably normal student life.
But the News of the World said publishing photos of the 20-year-old shopping at Tesco, riding his mountain bike and chatting to friends without his Scotland Yard bodyguard "does not mean open season for the paparazzi".
In September Prince Edward apologised for breaching William's privacy
A spokesman said the "totally innocent but
fascinating pictures" had been taken in a public place.
"Their publication is fully in accordance both with the letter and the spirit of the PCC code," he said.
William, who is 21 in June, is in his second year at St Andrews where he is studying the history of art.
The Palace and the media have been fighting a running battle over William's privacy ever since his 18th birthday and the end of a press agreement to protect his privacy while he was a child.
In September last year, the Palace condemned the "insensitivity" of a TV movie aired in the US which dramatised the years from the death of his mother, Princess Diana, to his arrival at St Andrew's College.
In 2001 Prince Edward promised to stop making TV programmes about royalty following controversy over his production company's filming of Prince William at university.
A royal row blew up after staff from the company were discovered filming William, Edward's nephew, during his first few weeks at St Andrews.
OK! magazine was censured over snaps of William in Chile
All other photographers and film-makers had by then left the town in line with a request from the Palace.
The intrusion by the Ardent crew was said by Andrew Neil, Rector of St Andrews and a journalist, to have "beggared belief".
Prince Charles was said to have been "incandescent" with rage at his brother, with newspaper reports describing him as swearing at "idiot" Edward during a telephone rant.
The celebrity magazine OK! was censured by the Press Complaints Commission in 2000, after it published unauthorised long-lens pictures of Prince William on a trip to Chile.
The media has also been warned in the past about their treatment of William's younger brother Harry, now 18, after allegations of under-age drinking and drug-taking.