An auction house in the US has said it has proof The Beatles reunited in the mid-70s in an abortive attempt to record a new album.
The site says the session took place in 1976
The site, momentsintime.com, is offering for sale a list of recordings and a tape reportedly made during 1976, but which were never released.
New York-based curator Gary Zimet said the band recorded five songs at a studio in Los Angeles.
But a spokesman for Sir Paul McCartney said he was "not aware" of any reunion.
And a spokesman for Beatles producer George Martin said he had "no knowledge" of the recording session, adding that the music producer was currently travelling and unavailable
The site said the five tracks recorded at Davlen Studios in Los Angeles were Happy Feeling, Back Home, Rockin'
Once Again, People Of The Third World and Little Girl.
It also alleged that "fifth Beatle" Martin, who had produced all of The Beatles' albums apart from Let it Be, had also been present during the sessions.
The tapes were said to have been "bulk erased" after the sessions ended in a row between the four band members.
He said one un-erased version of the session was being held in a vault in London's Abbey Road studios, where The Beatles had recorded their material in the 1960s.
Mr Zimet said the former co-owner of the studio, Len Kovner, and sound engineers could "independently confirm" the recordings happened.
The tape had been offered for sale by a former employee of the studio.
"I'm not sure exactly how he came by it but from what I understand he was one of the engineers present that day," he said.
He quoted a letter that from Mr Kovner that said: "This tape deserves its place in rock archives. The only copy is in a vault in Abbey Road."
Last month the same website offered for sale the copy of a John Lennon album that the singer had signed for Mark Chapman just moments before Chapman murdered him on a New York street in 1980.