David Birrell was admitted to hospital with a serious eye injury following the incident during Saturday's (02Oct10) performance at the Donmar Warehouse in London.
British reports suggest there was a fault with a prop gun used on stage, which was meant to fire blanks.
A spokesperson for the venue says, ""During the matinee performance of Passion on Saturday David Birrell sustained an injury to his eye for which he is currently being treated in hospital.
""Our priorities are to David's well being and recovery; and to theatregoers who have purchased tickets for performances in the coming days.""
All shows have been axed until Wednesday (06Oct10) at the earliest and an investigation is ongoing.