Mick Hawi shooting: Video shows moment bikie boss was executed

This is the moment former bikie boss Mahmoud "Mick" Hawi is executed in cold blood as he sits in his car outside a Sydney gym.

In CCTV obtained by 9NEWS, 37-year-old former Comancheros kingpin is seen climbing into his black luxury Mercedes-Benz four-wheel-drive outside a Rockdale Fitness First on February 15.

Moments later, a man clad in black approaches the driver's side window and fires a volley of shots at the helpless Hawi.

The assassin charges from the carpark and is believed to have fled in a grey Mercedes-Benz hatchback that was later found burnt out in nearby Kogarah.

Two masked men were later captured on separate CCTV running from the scene.

Hawi was rushed to St George Hospital but suffered multiple heart attacks and later died.

No one has yet been charged over Hawi's murder, described at the time by police as "serious, brutal and callous."

NSW Police today confirmed they were aware of the video. 

"Strike Force Amirs detectives are aware of the vision, and had previously obtained a copy, along with other footage taken in the area at the time," a police spokeswoman said.

"Investigations into the circumstances surrounding the shooting of Mahmoud Hawi are ongoing.

"Anyone with information that may assist police with their inquiries is urged to contact Crime Stoppers on 1800 333 000." 

Yesterday, it emerged that a 29-year-old man was arrested at Sydney Airport less than 24 hours after the shooting.

A pistol allegedly found at the man's home was tested and found not to have been used in the execution.

Hawi was convicted of the 2009 murder of rival bikie Anthony Zervas at Sydney Airport, but the charge was later downgraded to manslaughter and he was released from prison in 2015.

Hawi's widow Carolina Gonzales has applied to the NSW Supreme Court to extract sperm from her murdered husband's body.

The sperm is being stored at an IVF facility until the court rules the application.

Hawi was farewelled at a funeral the al-Zahra mosque in Arncliffe a week after the shooting, with some mourners clashing with police.

One police officer drew a Taser as he engaged in a verbal stoush with a man en route to the funeral.