Three hundred forged tickets were seized by IRFU stewards before the Ireland-France rugby international at Lansdowne Road on Saturday.
The tickets were were seized at the barriers leading to the entrance points at the stadium.
A spokesman for the Irish Rugby Football Union said there was now quite a sophisticated mechanism in operation to detect forgeries. "There are about seven security features embedded in the ticketing which enable the stewards to be as vigilant as they can," he said.
"Given the occasion, some will slip through, but by and large the defence mechanisms work."
He said a similar number of forged tickets had been seized before the Ireland-England game. He said the IRFU had invested significant amounts of money trying to counteract ticket-touting.
The spokesman welcomed recent comments by Taoiseach Bertie Ahern that he would look at the possibility of introducing legislation to deal with the problem.
"The IRFU would certainly sign up to any Government initiatives in this area," said the spokesman.
Recently in the Dáil, Mr Ahern was urged by Fine Gael leader Enda Kenny to introduce measures to eliminate the circulation of forged tickets and the sale of tickets on the black market.