London, Oct 16 (IANS): Singer Adele's tribute has been included in the "Freedom" documentary on late pop icon George Michael.

She was asked to join the project later than other stars and her tribute to the star will be aired during the opening credits, reports thesun.co.uk.

The project, on which Michael was working when he died, features contributions from stars including Kate Moss, Chris Martin and Naomi Campbell.

But at the 11th hour Adele insisted on entering a studio to ­capture her version of Michael's song "Fast love" for it.

Sources say the diva, who performed a slowed-down cover of the track at the Grammys, may now release it in memory of Michael, who died last Christmas at age 53.

A source said: "Adele did not feature until a very late stage. But George's best friend David Austin, who was making the film with him, asked her if she would be involved and she said yes straight away.

"She was a massive fan and wanted to make sure her tribute was perfect. The result was incredible and will be aired during the opening credits."

Adele, 29 -- who received a Brit Award for Best Album from Michael in 2012 -- has credited him as "one of the truest icons" after he inspired her from the age of 10.