The songs encapsulate the wrenching experience of having lost a great love — starting with anger and denial, and moving on through feelings of hurt and acceptance.

They are also probably the most lucrative expression of heartbreak ever recorded. Adele’s album, 21, has sold more than 17 million copies worldwide, netting her a £25 million fortune since its release last year. It remains No 1 in the U.S. charts after 22 weeks in the top slot, and has sold more than 4 million copies in the UK.

And, following the singer’s recent performances at the Grammys and the Brits, her record sales  show no signs of slowing down — executives claim a copy of 21 is sold every two seconds.

But a tantalising mystery remains: just who was the man who broke Adele’s heart? She says she wrote the album over a three-month period at the start of 2010 after the relationship had ended. Yet while Adele, 23, has been happy to refer vaguely to the inspiration for the album, she has never actually named the person in question.

Great love: While Adele, 23, has been happy to refer vaguely to the inspiration for the album 21, she has never actually named the man in question

There are a few clues. She said last year: ‘We just fell out of love … and I had to deal with the devastation of feeling like a failure because I couldn’t make things work.’

In another interview, she said: ‘He was a few years older than me. He made me feel alive … and made me really passionate about food, wine, film, sociology, history and travelling. He opened my eyes to a lot of things.’

But was it really a great love? The affair must have happened between the release of her first album 19 in 2008, and the beginning of 2010 when she went into the studio to record 21 — both albums being named after her age at the time.

He was a few years older than me. He made me feel alive … and made me really passionate about food, wine, film, sociology, history and travelling. He opened my eyes to a lot of things.

During that period, however, she has only been pictured with one possible suitor — a musician named Slinky Sunbeam — but she’s rubbished claims they dated. ‘Whoever this source is, they’re talking out of their ****. He ain’t my type,’ she wrote on her blog in 2008.

Given that Adele was fairly well-known by this point, had she been in a serious relationship, surely at least one photographer would have spotted the couple, say, going to the cinema?

And Adele has confused things further. In January 2008, she said she was single. A year later, she said she was still not with anyone and that she’d ‘had a relationship last summer that was rubbish, more of a fling’.

So was Someone Like You just an intense reworking of her feelings about a ‘rubbish’ fling from the summer of 2008? Or was there a Mr Right — who somehow went undetected — between early 2009 and early 2010?

Some Adele-watchers believe the truth may be that the album is her creation in more ways than one. One source who has spent several weeks attempting to find ‘the man’ told me this week: ‘My money is that she has either made it up or this was a case of unrequited love.’