The tapes were recorded during sessions for Let It Be

The 504 tapes contain about 80 hours of material, including 200 cover versions, Southwark Crown Court has heard.

Nigel Oliver, 55, from Slough, is on trial on charges of handling stolen goods. He is accused of trying to sell the tapes on behalf of two unknown men.

He has been found unfit to plead. The lost 1969 recordings were recovered in an undercover operation in 2003.

"These tapes have a huge commercial value," said Neil Aspinall, who manages The Beatles' Apple Corps label.

The tapes were stacked up in boxes on the floor of the house Rachid Bourammani Dutch investigator

"There's lots of very unknown stuff and music they wouldn't have recorded in a normal session," he told the court.

"For example, they covered over 200 songs on these tapes. Songs of the day, such as Bob Dylan."

The recordings were made for the band's final album, Let It Be.

Undercover operation

Oliver was arrested in January 2003 during an undercover operation set up by the International Federation of the Phonographic Industry (IFPI).

The court heard that he organised the transaction between two men in Amsterdam and two undercover officers in the UK, and was caught while waiting for his payment.

The recordings were found during a search of a house in Lisse, Holland.

"The tapes were stacked up in boxes on the floor of the house," Dutch investigator Rachid Bourammani said. "There were lots and lots of them."