Michael Jackson's new single was actually written 26 years ago.
This Is It debuted online on Monday ahead of the release of a documentary of the same name.
But it's now emerged songwriting legend Paul Anka penned the tune with Michael in 1983.
The track was originally called I Never Heard and was even released by singer Sa-Fire in 1991.
Michael's estate must now pay Paul, 68, half of the royalties.
‘We are thrilled to present this song in Michael's voice for the first time,' says a spokesman.
‘The song was co-written by the legendary Paul Anka. The song was picked because the lyrics were appropriate because of the name Michael gave his tour.'
Paul is delighted with the decision.
‘They did the right thing,' he says. ‘I don't think anybody tried to do the wrong thing. It was an honest mistake.'
This Is It will appear on a new greatest hits album, which is out on 27 October.