Canadian superstar Justin Bieber's scuppered birthday plans have been revealed.

The 'Baby' singer took to Twitter in the early hours of this morning to let his fans know he'd had the "worst birthday".

Insiders had previously claimed that Bieber's birthday debacle was down to a "confrontation" between the star's team and London club Cirque Du Soir security.

However, the marketing and PR director at the hotspot has revealed to Entertainmentwise that Bieber's birthday night came to an abrupt end because of a couple of underage members of his party - Jaden Smith, 14 and  Ella-Paige Roberts Clarke, 17.

Marketing manager Tom explained: "We, like all clubs in London, operate a strict age policy. As a few of the members of the party were under the suitable age of 18, the security team at Cirque Du Soir, London, clearly explained this rule and refused entry to the club for anyone who could not provide us with adequate proof of age.

He added: "Justin Bieber visits Cirque Du Soir regularly, and he and his friends are always welcome, as long the members of the group are legally old enough to enter the club. This was simply a matter of regulation that we must adhere to."

The star is in the UK at the moment as he takes his Believe world tour around Britain. Watch Justin Bieber's 'Right Here' lyric video below: