About 60 artworks dating from the 1930s and 1940s are on the market as Walt Disney's most famous creation prepares to celebrate its 75th anniversary.

The pictures have been identified as being from the cartoons Clock Cleaners and Boat Builders.

They would have been drawn by one of the "old men" of the Disney studios - probably Freddie Moore.

The drawings were in a private UK collection

The storyboards were acquired by a London-based animation art dealer from a woman in the UK who had owned them since she was a child.

They are on sale for about �600 each.

Storyboards are roughly drawn pictures which allow the director to plot out the animation before individual frames are drawn.

They have often been thrown away after use, but now collectors are buying them as investments which can increase in value by as much as 25% a year.

Disney designed Mickey - first known as Mortimer - during a train journey to Los Angeles with his wife Lillian.

There was a time when you couldn't have said the word Goofy in the company of a serious buyer, but those days have gone

Russell Singler, Animation Art Gallery

His public debut was on 18 November 1928 in the famous animation Steamboat Willie.

Russell Singler, director of the Animation Art Gallery, said it was a superb collection of historic artefacts.

"Pieces of this quantity and calibre rarely come on to the market," he said.

He said cartoon artwork was now being taken more seriously among serious art collectors - especially classic Disney items.

"There was a time when you couldn't have said the word Goofy in the company of a serious buyer, but those days have gone."