Former NSW State of Origin coach Graham Murray has died at the age of 58.

Murray had been in the intensive care unit at the Princess Alexandra Hospital in Brisbane after suffering a suspected heart attack.

It was the second time in less than six months Murray has been in hospital after spending a week in a coma following a heart attack in March.

The North Queensland Cowboys said on Twitter that their former coach had died and that their thoughts were with him.

"We can confirm Graham Murray has had his life support turned off," the club tweeted.

"However Graham is still with us and our thoughts and prayers are with him."

That illness forced Murray to step down from his role as head coach of Queensland Cup team Wynnum-Manly.

As well as his time at the Cowboys and the Sydney Roosters, Murray coached the Blues in the 2006 and 2007 Origin campaigns and had stints at the helm of the Leeds Rhinos in England, Super League outfit Hunter Mariners and the Illawarra Steelers in the NSW Rugby League.