Rory McIlroy was “surprised” after a fan grabbed one of his clubs as he was preparing to tee off in the Scottish Open at the Renaissance Club in North Berwick .

The golfer was chatting on the 10th tee with his caddie Harry Diamond and world number one Jon Rahm when a spectator walked on to the tee and pulled out his driver by its “St Bernard” headcover.

The driver remained in the bag, leaving the fan, who Rahm suggested might have been tired and emotional after a long night, with the headcover in his hands.

The fan then drew an iron from the bag and, as McIlroy, Diamond and Rahm did a double-take, he walked on to the tee, placed the headcover on the ground and shaped up to hit it before a marshal and security intervened.

According to an onlooker who spoke to the Scotsman newspaper: “When someone told him that he couldn’t do that, he replied by saying ‘Why not?’ At that point, the security people assigned to following the group moved in and took him away.”

McIlroy played poorly and shot a level-par 71 to miss the cut on one-under in a disappointing showing ahead of the British Open next week.

“You all saw it on TV,” said McIlroy as he packed his golf bag afterwards. “So you know what happened. I was surprised. But it was handled efficiently, and everything was OK. I had no idea who it was. Yes, there is a serious aspect to something like that,  but it was handled well.”

Rahm, who beat McIlroy by 10 shots over the first two days after rounds of 66 and 65, had his own theory on what prompted the intruder to act.

“Let me put it this way: You could smell the reason why he did what he did,” the reigning US Open champion said. “He was clearly not sober. I’m going to say it was vodka. I’m no expert, but he had a long night for sure.

“He probably thought it was a fun idea. And, to be fair, it was quite funny. At one point I thought he was going to Happy Gilmore the headcover.

“I don’t think it put Rory off. He hit maybe his best drive of the tournament off that tee.

“If anything, it put a smile on our faces. It’s a pretty good story to tell in the future.

“Security was good. But these things can happen. The guy had good timing.

“He walked in very confidently. We were all thinking, ‘Maybe he is supposed to be doing this’.

“We didn’t know. We thought he was from television or a magazine and was going to take a picture. Then we realised that was not the case when he started to tee-off with the head-cover.”

Police in Scotland said a 35-year-old man was taken to the Royal Infirmary hospital in Edinburgh.