Britain's Princess Diana and Prince Charles' unseen wedding photos are being auctioned in America.

Princess Diana

Princess Diana

Official royal photographer Lord Patrick Lichfield took the photographs for their wedding reception in July 1981 at Buckingham Palace, after the wedding ceremony at St Paul's Catherdral and now 14 images are being sold offering a glimpse inside one of history's biggest weddings.

The photographic memoirs have been put on sale in Cambridge, Massachusetts, U.S. by a British woman who worked as the assistant of Lord Lichfield, according to the Daily Express newspaper.

The items come with a letter of provenance, which is proof of the authenticity of the images.

Lord Lichfield wrote: "I was the photographic assistant to Lord Patrick Lichfield...the only photographer allowed to take informal photographs of the royal family and their guests when they returned to Buckingham Palace...for the wedding reception."

The photos still have stickers on them saying they are copyrighted to Lichfield who died in November 2005.

They include seven colour seven by five and seven glossy 10 by eight prints in black and white.

Most of them are of Diana in her wedding gown designed by British designer's David and Elizabeth Emanuel.

However, there are more rare uncandid citings of Britain's Queen Mother, Princess Anne, Princess Margaret and Prince Andrew.

And the most memorable is of Charles and Diana on the balcony of Buckingham Palace.

It's expected they will sell for at least £11,000.