One of the two Samoan men arrested by Vietnamese police over the killing of an Australian with reported links to Sydney’s criminal underworld outside a restaurant in Ho Chi Minh City has admitted that he was hired to carry out a hit on a rival.

Lorenzo Lemalu, 24, was gunned down outside the restaurant last Thursday, in a rare gangland murder involving foreigners using Vietnam as a base for their crime.

Shocking images of the shooting caught on CCTV show flashes from a gun wielded by a hooded man as Lemalu stumbles on a road. A second man also appears to have been shot.

Less than 72 hours after the shooting, Vietnamese police said they had caught two Samoan suspects, named by the country’s public security ministry as Steve Tafia and Vaa Vaa, who were “hiding in the border area between Vietnam and Cambodia”.

In a televised confession staged for the cameras, the heavily restrained Tafia said he and Vaa Vaa were “hired to come to Vietnam to look for two victims … in order for my friend to use a gun to kill him”.

Reading from a statement, he said Vietnamese police had thwarted his attempts to flee, adding that “escaping from the Vietnamese police was impossible, and I accept responsibility before the law”.

In comments that appeared to be heavily scripted, he urged any criminals planning to come to Vietnam to commit nefarious acts “to abandon the idea because you will be arrested immediately by the Vietnamese police”.