Police say members of the public who restrained a 45-year-old Ormeau man, who died soon after, at a Gold Coast restaurant on Friday night did "the right thing".

Witnesses said the man ran into the Thai Chim restaurant in Sanctuary Cove at about 7:15pm,  repeating, "Someone wants to kill me," as staff tried to remove him from the premises.

South eastern regional crime coordinator Detective Superintendent Brendan Smith said the man had been "affected by mental health issues or was in some kind of psychotic state", and police had no ongoing concerns for wider public safety.

"There was no person chasing this man. There was no person involved in threatening him," Superintendent Smith said.

"He was involved in two instances prior to his death where he interacted with some community members and took some property, and some of those persons were attempting to recover their stolen property. There were no threats."

Superintendent Smith said the man was trying to access the kitchen area of the restaurant when members of the public stepped in to help.

"I would suggest the persons in that restaurant who did restrain him have done the right thing," he said.

"They've protected other (people) in that restaurant because of that man's mental health and the fact that he was close to accessing weapons."

Superintendent Smith said it was not yet clear whether the man was suffering from mental health illness or was affected by some kind of drug psychosis.

He said the man had been in contact with authorities multiple times in the week leading up to his death in relation to mental health concerns.

"He wasn't known [to police] in respect to criminal activity," he said.