As if Russian Prime Minister Vladimir Putin doesn't have enough to do, his office moved Friday to quash stories that he attended — and even lip-synched — a mystery concert featuring an ABBA cover band.

Putin's spokesman Dmitry Peskov denied claims that Bjorn Again, a London-based cover band that performs songs by the 1970s pop group, gave a secret show on a remote military base for the prime minister.

"I can tell you officially and for sure Vladimir Putin never took part in any concert of the kind. He wasn't there," Peskov said.

But Bjorn Again's manager Rod Stephen is quite sure that his band is telling the truth about their strange gig that they detailed for the press.

Having flown from London to Moscow, then endured a nine-hour bus ride through the Russian countryside, they claim they arrived at a remote military barracks at about 5 a.m. There, a security guard instructed the band members that they were not to leave the stage during the show under any circumstances

It was weird, but when you're receiving $45,000 — a tab said to be paid for by the Kremlin — for an hour-long gig, you don't ask too many questions.

The show went well. The group sang 15 ABBA hits including Waterloo, Gimme Gimme Gimme and Dancing Queen. The shadowy figure behind the curtain seemed to enjoy it, as did the woman seated next to him.

The couple cheered, danced, and even threw their arms in the air during Mamma Mia when asked to by the band's resident Agnetha.

But it wasn't until after the performance that the four musicians became aware that the mysterious man who knew all the words to Super Trouper was one of the most powerful men in the world: Putin.

And though a lace curtain separated the band from the elite audience for the hour-long, high-security show, group member Aileen McLaughlin said at one point the spotlight flashed on the audience and band members saw Putin.

"They were clapping and swaying, and putting their fingers in the air, that kind of thing," said McLaughlin. "He (Putin) had good rhythm. He was shouting 'Bravo, Bravo!' after the songs."

But while Peskov and the Kremlin denied the charges that the performance ever took place, they didn't deny that Putin occasionally rocks out to Super Trouper or Dancing Queen when the mood strikes.

"I have no doubt that he likes some music of Abba," Peskov said. "But he simply wasn't there."

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Click here for ABBA's 'Super Trouper' Lyrics

The Associated Press contributed to this report.