Adele reportedly turned down millions to record the 'Spectre' theme song.
The Grammy Award-winning artist - who co-wrote and sung the soundtrack for 'Skyfall' in 2012 - didn't reprise her singing duties for the forthcoming James Bond movie because it would be hard to beat her global smash, despite being the top choice of Daniel Craig.
A source told the Daily Star newspaper: "Adele was James Bond himself's first choice. Daniel Craig was really keen and (director) Sam Mendes was 50/50 over whether to use her or a fresh voice.
"Filmmakers were prepared to offer millions but Adele was never up for it.
"How do you top a worldwide hit like 'Skyfall' any way? It was too big a risk."
The 'Rolling in the Deep' hitmaker is currently focused on the launch of her much-anticipated third studio album and recently met up with One Direction's tunesmith Jamie Scott to get some advice.
A source added: "She has a mass of material but can't settle on what. She spent a day with 1D songwriter Jamie Scott but that probably won't see the light of day either."
The 'Spectre' theme song, entitled 'Writing's On The Wall', has instead been penned by Sam Smith, who recently said he hopes his tune proves to be "timeless".
He said: "For me it's about making the most timeless songs that will last forever. I've given it a good f**king shot. I love the song.
"With Bond, if you go back through the songs not all of them won Oscars, even the most timeless ones."