Footage emerges of man who died after being held down by Bunnings security guard

An alleged thief who was tackled by Bunnings security guards 12 hours before he died in a Melbourne hospital told them he could not breathe, shocking footage has revealed.

Anthony Georgiou, 31, was leaving a Bunnings Warehouse in Frankston, south of Melbourne, on September 12 when he was pinned down by two guards.

Distressing mobile phone footage obtained by A Current Affair shows blood coming out of the father-of-one's mouth as he pleads with security to let him go, the Daily Mail reports.

Pinned down on his front with his arms twisted behind his back, Georgiou says: "Somebody help me, please! Get them off me! Help me!"

A female bystander can be heard telling the guards to stop restraining him.

"You need to be careful. He's saying he can't breathe, the woman tells the two men.

"It's called positional asphyxia. If you put pressure on his back while he's facing down, he can actually die. He's saying he can't breathe."

There is no suggestion that Georgiou was suffering from positional asphyxia - when people find themselves unable to breathe in certain positions - before he died.

The guards eventually ease off of Georgiou, who is alleged to have been trying to steal something from the store before he was caught, but he still claims to be having trouble breathing.

Police arrived and called an ambulance, with paramedics taking Georgiou to hospital in a critical condition. He died 12 hours later and leaves behind a four-year-old daughter.

In a statement, Georgiou's family said they were in a "state of shock and grief", branding his death "unnecessary".

Bunnings declined to comment when contacted by Daily Mail Australia.

A coroner is investigating.