Knights star under investigation for crazy sheds biff

The NRL will investigate an incident between Jack Hetherington and Reed Mahoney in the tunnel at Accor Stadium during the closing stages of the Bulldogs' 36-12 win over the Knights on Sunday.

The pair were both sin-binned with just minutes left to play after they got into a scuffle in response to Jaeman Salmon laying a dangerous tackle on Jackson Hastings.

After being marched to the bin when they continued to trade verbal barbs, Hetherington came out of the dressing room to confront Mahoney in the tunnel and had to be dragged away by Bulldogs' staff.

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Vision broadcast on Fox League showed Hetherington shaping up to Mahoney in the sheds and appearing to throw a punch. 

Speaking on Nine's broadcast, 9News and Sydney Morning Herald reporter Michael Chammas revealed that the NRL is looking into the incident.

"Jack Hetherington allegedly came out of the sheds as Reed Mahoney was coming up the tunnel and confronted Reed Mahoney," he told Nine.

"The NRL are investigating that it perhaps got physical and they want answers why Jack Hetherington made his way up to Reed Mahoney in the tunnel."

It is hard to know whether Hetherington was acting in a serious or joking manner as he can be seen smiling but clearly pushes Mahoney.

Asked about the incident in his post-match press conference, Knights coach Adam O'Brien claimed he knew nothing of the altercation.

"No, nothing, I don't even know what you are talking about," he told media.

"I don't know anything about this."

Bulldogs coach Cameron Ciraldo was also pressed about what he knew.

"I have heard some stuff in there, but I don't think it is too serious," he said.

"Jack is a good fella. I have known Jack for a long time. He is a good guy. Sometimes he gets emotional but he is a genuinely good person so I don't think there is too much in it.

"Reed didn't go into much detail. I haven't had a chance to talk to him but it's done now.

Of the double sin bin he added: "It was the longest last four minutes of any game I have seen so I am glad they did something to get it going again".

"I think they were just cooling it down but it's done now [and] we will move on."