A photographer says he is “contemplating” legal charges against Colin Farrell over allegations he attacked him on a red carpet.

Farrell is said to have been furious when London-based freelance photographer Joe Alvarez, 38, screamed at the star’s sister to get out of the way on the red carpet at the Toronto Film Festival.

Alvarez says as well as a verbal assault, Farrell then grabbed him by the back of the neck in front of the press pack.

“I was just shouting ‘clear the red carpet,’” insisted Alvarez. “He is obviously a live wire, I did not insult his sister. I did not swear at his sister.”

The confrontation came as Farrell appeared for the premiere of Triage along with his sister Claudine, who acts as his assistant.

Alvarez admits: “Everyone was shouting – and okay, I was shouting louder.”

Fellow photographer Jorge Rios also said everyone was yelling, but when Alvarez “screamed ‘get off the carpet’ everybody stopped.”

Then Farrell pointed at Alvarez, “went right up to him and grabbed him by the back of the neck and said ‘you don’t yell at my sister like that’,” Rios said.

When Alvarez apologised, Rios claims Farrell said: “It does not matter, you should not be yelling at any woman like that.”