Michael Jackson’s ‘new’ single This Is It was co-written back in 1983 with Paul Anka- it has emerged.

The veteran crooner- who wrote classic tracks like My Way- was shocked when he heard the song and will now be awarded 50% of royalties by the MJ estate.

He told TMZ the trustees had apologised for “ripping off my song” and added “they've realised it's a mistake.”

The song was originally called I Never Heard and was released by artist Safire in 1991.

Anka revealed that he had worked on the song with Michael in California in the early 80s. The Jackson brothers have since added backing vocals to it.

This Is It is the title track to a documentary of the same name released later this month. A soundtrack album also features an alternate version of the song.