The 41-year-old man, surnamed Wong, was exercising at an outlet of 24/7 Fitness at Tin Ping Shopping Centre when the accident happened at around 6.30am on Tuesday.

A preliminary police investigation showed the victim tried to push up the barbell, but it seemed he did not have enough strength and it fell on his chest.

According to the force, Wong was exercising alone at the time and nobody noticed the mishap immediately.

"Several minutes later, he was found unconscious with the barbell on his chest," a source said.

Wong was sent unconscious to North District Hospital for treatment, where he died at 12.41pm on Sunday.

The police source said a death inquest was likely to be carried out and officers from the Tai Po miscellaneous inquiry unit would compile a death report.

The weight-training machine is a common piece of gym equipment used to strengthen muscles in the chest, shoulder and legs.

Personal trainer Zico Wong Lok-hong told the Post last week that he believed the victim had not applied the machine's safety catch, which would have stopped the barbell at a predetermined height.

He said gym-goers sometimes did not set the lock on the machines to save time.

The Post has contacted the fitness centre for comment.