Adele's lent her vocals to a "filthy" rap tune.
The 'Someone Like You' singer is set to shock fans if she releases the track - a world away from her heart-wrenching ballads - which features her swearing repeatedly.
Rapper Tinie Tempah said: "I know Adele really well and she was with me and [producer] Labrinth in the studio when we recorded 'Earthquake'.
"She also has this rap she recorded. It's really filthy."
Tinie, 24, says the track was "an experiment'' and he isn't sure if it will ever be released, especially as Adele has joked she'll start legal proceedings if he leaks it.
Speaking in an interview on TV show 'Alan Carr: Chatty Man', to air in the UK tonight (01.11.13), he added: "She said if we ever play it to anyone she will sue us."
Adele, 25, took some time out after the global success of her second album '21' - having her first son, Angelo, with partner Simon Konecki in October 2012 - but she has recently been in the studio with songwriter Ryan Tedder, who claims her new material is sounding great.
Ryan - who wrote 'Rumour Has It' and 'Turning Tables' with the star - said: "Adele sounds even better than before. I love where she's at, she's still my favourite artist in the world.
"I would press pause on my entire life if it meant I could go into the studio for a month straight with her."
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