A bizarre indie film starring Daniel Radcliffe as a farting corpse with supernatural powers that turn him into a flatulent jet ski has left audiences at the Sundance Film Festival perplexed.

Paul Dano co-stars in Swiss Army Man as Hank, a suicidal castaway whose zest for life returns after the dead body washes up on the beach and he discovers he can use it as a gas-powered escape vehicle.

What a gas ... Paul Dano contemplates his new best mate (Daniel Radcliffe). Credit:Sundance Film Institute

But that is only the beginning of the corpse's hidden talents. As well as functioning as a portable water tank and a weapon (the body shoots objects from its mouth), Radcliffe's character, Manny, is also able to direct Hank back to civilisation with a penis that apparently doubles as a GPS.

Eventually Manny comes partially back to life and the pair form a bond that goes considerably beyond what would conventionally be described as a bromance.