Golf Channel reporter Steve Sands broke the story on air shortly after Reed and four ball partner Webb Simpson lost their third consecutive match.

The pair were defeated 5 & 3 by C.T. Pan and Hideki Matsuyama and the incident allegedly happened as they were leaving the 15th green.

After Sands reported the altercation, the story gathered momentum on social media and popular podcast account, ForePlayPod, which tweeted a screen shot of a statement allegedly from Karrain.

 “As a caddie one of your jobs is to protect your player,” the statement read.

Patrick Reed and caddie, Kessler Karain, during the Presidents Cup. PHOTO: Getty Images.

“And unlike several other sports, in golf fans can get pretty close to athletes.

“We have been known for having fun with some good banter but after hearing several fans in Australia for three days some had taken it too far. I had had enough.

“And this gentleman was one of them. Riding on the cart, guy was about 3 feet from Patrick and said, “you f**king suck”.

“I got off the cart and shoved him, said a couple things, probably a few expletives. Security came and I got back in the cart and left.

Karain says there would not be one caddie that would blame him for what he did. PHOTO: Getty Images.

“I don’t think there’s one caddy I know that could blame me. Unless his bones break like Mr Glass, the most harm done was a little spilled beer, which I’m more than happy to reimburse him for.”

The incident was investigated at a meeting with PGA Tour Commissioner Jay Monahan and Karain was banned from caddying for Reed in the final day singles matches.

"Following an incident that took place on Saturday at the Presidents Cup involving Kessler Karain and a spectator, Karain will not return to caddie for Sunday's final round singles matches. We will have no further comment at this time," a PGA Tour statement read.

In a brief one line statement Patrick Reed said: "I respect the Tour's decision. We are all focused on winning the Presidents Cup tomorrow."

Reed has been taunted by Cup fans all week after his rules violation at the Hero World Challenge in the Bahamas last Friday. Reed was slapped with a two-stroke penalty during the third round when he played a ball from a sandy waste area and was deemed to have improved his lie.

Video of the incident showed Reed moving sand twice in the backswing of a practice swing. As the video went viral, Reed has increasingly faced accusations of cheating.