Daniel Radcliffe's new starring role has hit an embarrassing hitch - he can't ride his character's motorcycle.

The Harry Potter star is shooting British TV drama My Boy Jack and part of the role requires Radcliffe to ride a motorbike. But Radcliffe does not know how to operate the vehicle, according to British newspaper The Independent.

A source tells the newspaper, "Daniel can't ride the bike on set but we have stuntmen and doubles who can do that for him. We do use Daniel for the close-ups because all he has to do is sit on the bike whilst it's not moving."