It's what every Punchdrunk theatre fan craves: a one-on-one encounter with a cast member in one of its interactive, site-specific performances.

But visitors to the company's Temple Studios venue in London on Tuesday night got more than they paid for when they came face to face with the Hollywood actor Andrew Garfield, making an unannounced cameo.

Pictures of the Social Network star emerged on Twitter and Instagram on Wednesday, showing Garfield in full costume for Punchdrunk's current show, The Drowned Man, chewing seductively on a stick of straw.

Subtitled A Hollywood Fable, The Drowned Man relocates the destructive love stories of Georg Büchner's Woyzeck to a seedy 1960s film underworld of trailer trash and treasure, recreated across four floors of a former sorting office behind Paddington station. Having opened in 2013, the show is now booking until at least June, emulating the success of Punchdrunk's long-running US production Sleep No More, which has occupied a block of Manhattan warehouses since 2011.

Garfield, 30, is in London to promote his new film, The Amazing Spider-Man 2, in which he co-stars opposite his girlfriend Emma Stone.

Born in Los Angeles but raised in Surrey, the British-American actor starting acting as a teenager, later playing in Kes and Romeo and Juliet at the Royal Exchange theatre in Manchester. In 2006, he was named outstanding newcomer at the Evening Standard theatre awards, while his performance as Biff Loman in a March 2012 Broadway revival of Death of a Salesman earned him a Tony award nomination. Fans will be hoping his Punchdrunk outing may have given him a renewed taste for the stage – and not just hay bales.