The Libertines pull out of show two hours after it was scheduled to start due to 'medical situation'

Fans fear Pete Doherty has relapsed after getting clean in rehab last year

Pete Doherty and Carl Barat perform at Glastonbury 2015 (Getty Images)

The Libertines were forced to pull out of a London gig last minute due to a “medical situation” hours after they were meant to appear on stage.

The band were scheduled to play a set at the Electric Ballroom in Camden at 9.15pm, but did not appear on stage. At 11.30pm a spokesman told the crowd: “Due to an emergency - a medical situation - tonight’s show is being postponed.”

He later said a new date would be announced on Friday, The Guardian reports.

The band later issued a statement on their Facebook page about the incident, saying they would have to postpone their shows at the Electric Ballroom and the Ritz in Manchester.

They apologised to fans “wholeheartedly” and assured both shows will be rescheduled “as soon as possible”.

Due to unforeseen circumstances tonight the Libertines have had to postpone their sold out shows at the Electric...

Posted by The Libertines on Thursday, 10 September 2015

Controversial frontman Pete Doherty is believed to have gone missing following the cancelled show.

A representative for the singer said he had "no comment" in regards to the Doherty's whereabouts.

The 36-year-old has had a history of drink and substance abuse, often speaking openly about his problems with addiction. In November, he checked himself into a rehabilitation centre in Thailand.

Writing in The Independent, he said: "This is the first time I've chosen rehab for myself, and got clean. Now I want to help others do the same."

The cancellation of the gig due to a "medical situation" has alarmed some fans:

Doherty has been in prison three times, had at least 15 court appearances, a conviction for burglary and more than 26 drug charges.

The Libertines have been playing a number of small-scale gigs in support of their latest album, Anthems for Doomed Youth, their first for 11 years following their comeback show last year at British Summertime Hyde Park.