Twitter might have revealed the man who attacked Rupert Murdock during a Home Affairs Committee hearing.

A man has been apprehended by police after he went after Murdoch with a pie, while Murdoch's son James was answering questions posed by British MPs. The man is believe to be @JonnieMarbles, a self-proclaimed anarchist who earlier tweeted that he was present at the hearings.

Right before the attack, Marbles made an incriminating tweet.

It is a far better thing that I do now than I have ever done before #splat, said Marbles, who describes himself as Activist, comedian, father figure and all-round nonsense. Tweeting in an impersonal capacity tweeted right before the incident.

Video of the incident is below.

There was only a 10-minute recess after the event, during which the other spectators were removed from the room.

Murdoch's wife Wendi stood up and tried to block the attacker, and appeared to punch him in defense of her husband.

James Murdoch was shocked when the person attacked his father. Rupert Murdoch didn't seem to realize what was happening until his wife came to his aid.

The man held by police was covered with pie filling.