Actor Laurence Fox stopped a performance of The Patriotic Traitor at London's Park Theatre this week to berate an audience member who was heckling him.

Fox, the son of veteran actor James Fox and nephew of Edward, is starring opposite Tom Conti.

At the March 8 performance, Fox broke the fourth wall and deviated from the script to advise the audience, "I won’t bother telling you the story because this c*** in the front row has ruined it for everybody."

He did not return for the stage bows at the end of the show. In a subsequent appearance on Radio 4's Today Programme, Fox explained what had transpired: "It was a very emotional part of the play and I was very upset about it. What happened was, the gentleman in the theatre started muttering and heckling early on during the play and then towards the end started telling me to f-off and sort of moaning about various things. It became so loud and so impossible to deal with."

He added, "It's not an interactive, stand up comedy show and therefore if someone is hellbent on heckling they are ruining it for everybody. So it becomes an unperformable play. The play stops at that moment because that person is defying the device of what the theatre is."

However, he admitted that he regretted his actions. He said he had spoken to his father, who advised him to have a little speech prepared, perhaps politely suggesting that the audience member leave or talk about it afterwards.

The Park Theatre issued its own statement, saying, "Park Theatre takes the welfare of its performers, staff and patrons very seriously. We are investigating the incident, and have no further comment at this time."

The run continues through March 19. For further details, visit parktheatre.co.uk/whats-on/the-patriotic-traitor.