Adele is yet to tell her songwriters whether their work has made it on her upcoming album.

The 26-year-old star's forthcoming third studio album is to be released next year after being pushed back, and US songwriter Diane Warren - who has worked with Beyonce Knowles, Sir Elton John and Whitney Houston - insists she doesn't know if the tracks she recorded with the singing sensation will make it.

She said: ''I flew to London to work on new stuff with Adele last year.

''We did some great songs but I don't know if they've made the record. I don't think anybody does.''

Diane - who has also won a Grammy Award for her work and been nominated for six Academy Awards - admitted she isn't expecting to find out whether her songs are on the 'Some Like You' hitmaker's album anytime soon because the star wants to take time to ensure the record is spot on.

She added to The Sun newspaper: ''She has a mind of her own. Nobody rushes Adele or makes decisions for her, which is probably why she's a great artist. She wants to get it right.

''She was singing her ass off when I was in the studio. Her voice was spectacular.''

While Adele - who won an Academy Award for her James Bond song 'Skyfall' last year - hasn't released a record since 2011 album '21', she was recently said to be earning £80,000 a day through two companies, according to accounts.