Bjorn Ulvaeus was knocking back whisky when he wrote 'The Winner Takes It All'.

The ABBA star - who gave up booze back in 2007 - has revealed he rarely wrote songs while under the influence of alcohol but he was drinking whisky when he wrote the band's huge 1980 hit and he's amazed the song came out well.

He told The Times newspaper: "I wrote that song very quickly while drinking whisky during my drinking days. I rarely wrote while intoxicated because you look at the words the next day and it's garbage.

"But most of 'The Winner Takes It All' is actually good. It's not a personal story, but I tried to find the detail of a real human pain."

Bjorn began his ascent to global fame when he won the Eurovision Song Contest for Sweden with the song 'Waterloo' with ABBA alongside ex-wife Agnetha Faltskog as well as Anni-Frid Lyngstad, and Benny Andersson back in 1974.

He went on to insist that although he did enjoy a few drinks during the band's hey day - ABBA were never a troublesome group and the worst thing they ever did was fail to tidy their hotel rooms.

Bjorn said: "I can assure you there are no hidden ABBA scandals, no blemish on our image …

"There were instances when we didn't leave hotel rooms in quite the order they were in when we came," he says rather adorably. "But nothing like the Who driving a Rolls Royce into a swimming pool."

Bjorn's ABBA co-star Benny Andersson is also sober after giving up booze and he previously called it the "best decision" he's ever made.

According to the Daily Mail newspaper, Benny said: "I wasn't feeling well without alcohol, so I knew that I was in trouble.

"I sought help and I got it. I knew that if I continued drinking there was a risk I would lose everything. If you drink enough for a long enough time, you will lose things ..

[Giving up alcohol is] one of the best things I've done. Quitting smoking was OK too. I quit smoking on my 40th birthday. Quitting drinking was a necessity. It was getting in the way of everything, as it does. It takes up all the space, all the time. So it's really something to get off your shoulders. It feels good."