The man was found lying on waste ground off the Falls Road in west Belfast with his hands bound behind his back and cloth wrapped round his head. Officers found he had been shot in the head.
The body was discovered after people heard shots at about 1am behind St Galls Gaelic Athletics Association Club in Milltown Row. It is believed the man was killed at the scene, and police do not believe he had been tortured.
Detectives had been searching for Mr Bennett, from Upper Meadow Street, since Tuesday when he was reported missing. On Thursday, the Royal Ulster Constabulary searched a flat in the New Lodge area.
At a news conference at a Belfast police station yesterday, Chief Inspector Ernie Waterworth said it appeared Mr Bennett knew the callers at his girlfriend's home in Clifton Park Avenue, and told her he would return "within 15 minutes".
Twenty detectives and forensic experts were keeping an open mind about the murder, and did not comment about suggestions that Mr Bennett was an informer, or whether the shooting was even committed by republicans. But Martin Morgan, an SDLP councillor in north Belfast, was more confident about identifying the person or persons responsible, saying terrorists were holding communities in a grip of fear.
He said: "The disgraceful manner in which Mr Bennett was murdered and the disgraceful manner in which his body was left to lie on waste ground certainly leads one to believe republican paramilitaries were behind this cruel and callous murder."
Mr Morgan said his message to the republicans responsible was that the people of Northern Ireland had clearly stated they no longer wanted violence. "It is about time these people took heed of that," he added.
The Sinn Fein president, Gerry Adams, sent his condolences and regrets to the victim's family. The West Belfast MP said: "Obviously this is a terrible thing for any family regardless of what is involved, or who is involved, or why this man was killed."