This is the shocking moment a British man is hurled to the ground by two motorcycle snatch thieves trying to grab his girlfriend's gold chain.

The middle-aged tourist was riding the bike with his partner on the back in Phnom Penh, Cambodia, last Tuesday (October 8) afternoon.

Two alleged thieves noticed his woman's gold necklace then raced alongside them before reaching out to pull the jewellery from her neck.

However, they dragged her to the side of the bike and clipped the scooter's front wheel, causing the British man to lose his balance.

The rider, who did not want to be named, slammed face-first into the ground before his partner landed on top of him.

He suffered cuts and bruises in the crash. He reported the attempted theft to the local police who were ''friendly but not optimistic'' about catching the two crooks.

The Brit said: ''I was driving with my girlfriend on her motorcycle on street 163 just after the mermaid roundabout.

''My girlfriend has a very small gold necklace, I have told her so many times to never wear it when she is driving, it was covered up by her jacket she wears but unfortunately, they must have seen it."

''Two men came up quickly from behind and tried to rob us. They failed but unfortunately, I crashed in the attempt and my body was pretty beaten up from the fall."

My girlfriend landed on top of me so she is fine. I always wear a GoPro while driving just in case of any problems. I have clear footage of the incident and one of the men's faces and their motorbike and registration number.

''We went to the police with evidence. They were polite but I don’t feel hopeful. I definitely don’t want anyone else to have this happen to them as they may have far more serious injuries and it could be far worse."

''Luckily I always wear a full facial crash helmet, as when I hit the concrete my face hit first, very, very hard. "

''Someone will definitely know these men.''

Cambodian capital Phnom Penh, one of the most poverty-stricken cities in South East Asia, has suffered an epidemic of motorcycle snatch thefts in recent years.

The crooks mostly operate in gangs by riding alongside their victims, who are also on the moped, then snatching their belongings and causing them to crash.

Phnom Penh Municipal Police Chief Sar Thet said previously that the authorities were committed to tackling bag-snatching.

''We are taking tough measures to reduce the cases. We have clear measures to prevent bag-snatching,'' he said.