Two men have been arrested after a Sydney underworld figure was shot dead in Vietnam.

Lorenzo Lemalu, 24, a senior leader of the notorious Coconut Cartel and former associate of the Alameddine crime family, was ambushed and shot outside a restaurant in Ho Chi Minh City on Thursday night.

CCTV captured Lemalu's final moments standing with a group on a footpath along a busy dining strip before he was gunned down at point-blank range in front of shocked diners.

Fellow Coconut Cartel associate Sam Sauni, 27, from Sydney's south-west, was seriously wounded, but survived.

On Tuesday, the Vietnamese Ministry of Public Security confirmed in a statement that two suspects, believed to be Samoan nationals, had been arrested.

'Currently, law enforcement agencies are focusing on investigating, verifying, and strictly handling the individuals involved in accordance with the law,' a statement to ABC News read.

It is understood that no charges have yet been laid. 

Daily Mail has contacted Vietnamese Ministry of Public Security for further comment.

It is understood that Australian Federal Police are attempting to verify the arrests.  

AFP and NSW Police both declined to comment on the investigation or the arrests. 

Police in Vietnam launched an investigation following the death of Lemalu, and on Saturday, released photos of two men they initially said were Australian nationals. 

The pair left Ho Chi Minh City in a taxi, before getting out near a supermarket in Tay Ninh, a town near the border of Cambodia, according to the police alert. 

It is currently unclear whether the pair previously pictured by police were the same two suspects arrested on Monday.

CCTV posted online showed the moment Lemalu was gunned down by a hooded gunman in a busy dining precinct.

A wounded Lemalu fled into a nearby restaurant, where he collapsed.

As shocked diners ran for cover, another victim fell onto the road but managed to crawl onto the footpath.

He was then dragged into a restaurant by a bystander to get help.

Another man was seen crouching down next to Lemalu's bloodied body inside a restaurant, trying to render first aid while speaking to staff.

Another photo shows paramedics desperately working to revive Lemalu.

Lemalu was a former member of Proper 60, a western Sydney-based gang linked to the Alameddines led by Ali Younes aka Ay Huncho and had the group's name tattooed across his stomach.

It is understood Lemalu fell out with the Alameddines some time after fleeing Australia four years ago and began directing the Coconut Cartel's activities from South-East Asia.

The Coconut Cartel is a breakaway gang locked in an underworld crime feud with the Alameddines over control of the Sydney drug scene.

The deadly shooting has sparked various theories  over who was responsible.

Messages obtained by SCN Worldstar and reportedly sent by members of the Alameddine network suggest they claimed credit for the execution.

'That's what happens when Coconuts try (and) fight the people that made them,' a message read.

But not everyone believes the execution is linked with the Sydney gangland wars, in the wake of a series of firebombings and drive-by shootings across the city in recent months.

'The big rumour is they ripped off some Albanians and that's why he was killed,' a gangster living overseas told the Daily Telegraph.

The Coconut Cartel has claimed online that the shooting was a case of mistaken identity.

'Let's clear up the air; this was not an attack from almo claiming it. It was an accident..... Coconut Cartel here and we're still coming for you forever strong,' a post read