The band's back catalogue was uploaded yesterday to iTunes, Spotify and the Amazon MP3 service.
However, the records have now been removed from iTunes, although they remain on Spotify and Amazon.
It has emerged that the albums available were bootleg recordings not authorised by KLF stars Bill Drummond and Jimmy Cauty. It is not yet clear how they came to appear on the legitimate sites.
The band deleted their back catalogue after quitting the music industry in 1992.
At the time, they released the statement: "For the foreseeable future there will be not further record releases from the Justified Ancients of Mu Mu, The Timelords, The KLF or any other past present and future name attached to our activities. As of now, all our past releases are deleted."
Drummond and Cauty later founded The K Foundation, burnt a million pounds and, in 1997 as 2K, released the single 'F**k The Millennium'.
> 5 incredible The KLF moments, from burning £1m to Doctor Who tribute
Listen to The KLF's 'What Time Is Love?' below: