Fred Daly was the last Irish winner of the Open in 1947

"Royal Portrush is fantastic course and I looked at it in great detail about five or six years ago," said the R&A's Director of Championships David Hill.

"It would be a fantastic venue, but only for about 15,000 people a day."

Royal County Down hosts the Walker Cup in September but a 10,000 daily maximum attendance figure has been put on that.

"The Championship Committee would love to find new venues, but there would have to be an amazing investment to consider taking it back to Northern Ireland.

"The Seniors Open was at Portrush and with 6,000 people we were struggling.

"I was talking to Padraig and he would love the Open to come back to Ireland but somebody would need to approach us about the level of investment involved.

"It would have to be an amazing amount to consider taking it back to Portrush - it's jammed with normal holidaymakers as it is," said Hill.

The K Club, near Dublin, was the first Irish venue to stage the Ryder Cup last September but Hill added: "It's referred to as the Open Championship played in Great Britain."

"That's where it lies at the moment, but it's never a closed book."

Harrington became Ireland's first winner of the title since Fred Daly in 1947 when he beat Sergio Garcia in a play-off at Carnoustie on Sunday.

The last time the championship was staged in Northern Ireland was when Max Faulkner triumphed at Royal Portrush in 1951.