Freddie Mercury stormed out of recording sessions with Michael Jackson because he insisted on bringing his pet chimp to the studio.

The two late music icons came together nearly 30 years ago to duet on 'There Must Be More To Life Than This', an uncompleted track that had been left in a vault to gather dust.

The song - released this week - was eventually discovered by Freddie's Queen bandmates Brian May and Roger Taylor who decided to complete it with the help of producer William Orbit and include it on new compilation LP 'Queen Forever'.

In an upcoming new book by showbiz writer David Wigg - who knew Freddie Mercury well - he reveals: ''Freddie got very angry because Michael made Bubbles sit between them and would turn to the chimp between takes and ask, 'Don't you think that was lovely?' Or, 'Do you think we should do that again?' After a few days of this, Freddie just exploded ... 'I'm not performing with a f***ing chimp sitting next to me each night.'

''He phoned his manager and told him to 'get me out of this zoo.' Freddie then flew back to London, leaving the track musically unfinished.''

'There Must Be More to Life Than This' was first penned by Freddie in 1981 and he worked on it with Michael in 1984 in Los Angeles.

A version of the song did appear on Freddie's 1985 solo album 'Mr. Bad Guy' in 1985.

Talking about the finished duet, Orbit recently said: ''Hearing Michael Jackson's vocals was stirring. So vivid, so cool, and poignant, it was like he was in the studio singing live. With Freddie's vocal solo on the mixing desk, my appreciation for his gift was taken to an even higher level.''

Two other previously unheard tracks which appear on 'Queen Forever', Giorgio Moroder collaboration 'Love Kills' and 'Let Me In Your Heart Again' which was written by Brian May.