Michael Jackson's new song, This Is It, accompanied by video footage from the forthcoming movie of the same name. Courtesy Sony Music Entertainment
The "new" Michael Jackson track premiered on Monday was written in 1983 by the star and singer Paul Anka, it has emerged.
Few details about This Is It - the first track to emerge since Jackson's death - were originally released.
But later on Monday, the Jackson estate confirmed Anka had co-written the song - originally called I Never Heard - after he had threatened legal action.
A version of the song was recorded by Puerto Rican singer Safire in 1991.
I don't think that anybody tried to do the wrong thing - it was an honest mistake
Jackson and Anka wrote the track for possible inclusion on the latter's 1983 album Walk A Fine Line.
Anka told celebrity website TMZ that Jackson then "stole the tapes" from his studio.
Anka, 68, told the Associate Press news agency that, after he complained that he had not been credited, Jackson's estate moved quickly to acknowledge his involvement and promised him 50% of the song's profits.
"They did the right thing," he said.
"I don't think that anybody tried to do the wrong thing - it was an honest mistake."
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