LONDON – Police raids in England and the Netherlands on Friday recovered what could be about 500 original Beatles tapes that were stolen in the 1970s, including some never-released tracks.

British police said the tapes were “priceless,” and that the only such recordings that have been heard before were bootlegs.

Dutch police, who recovered all the tapes in the Netherlands, agreed, but said they were still analyzing the material.

“We’re currently investigating whether they really are the originals, but it appears to be so,” said prosecutor spokesman Robert Meulenbroek in Amsterdam. “There are about 500 tapes, so there’s quite a bit to research.”

Five people were arrested in separate police raids in England and Holland. Their names were not immediately released.

The tapes contain what are known as the “Get Back” sessions, which were to become an album in 1969 before the project was shelved. Some of the songs, including “Get Back” itself, became part of the “Let It Be” album, said London police.

For many devoted fans and collectors, the original reel-to-reel tapes would be a valuable recovery by Apple, the Beatles’ record company. Over the years, pirate copies had turned up in Britain, continental Europe and the United States.

The International Federation of the Phonographic Industry led the investigation with help from London detectives. They first identified suspects who were thought to have been involved in the theft and handling of the tapes. Further inquiries across Europe led to the joint operation by British and Dutch police.

Two people were arrested Friday in West London, and three at an undisclosed location south of Amsterdam, police said.