Former Comanchero bikie chief Mahmoud 'Mick' Hawi has died after being shot outside a gym in Rockdale, in Sydney's south.
Officers were called to the incident at the Fitness First gym on West Botany Street shortly after midday.
Mr Hawi was in his black luxury four-wheel drive when he was shot at least half a dozen times.
He went into cardiac arrest and was taken to nearby St George Hospital.
Sources say Mr Hawi has kept a low profile in recent years after he served a prison sentence for manslaughter over the death of Hells Angel bikie Anthony Zervas in a brawl at Sydney Airport in 2009.
During the airport brawl Anthony Zervas — the brother of Hells Angel bikie Peter Zervas — was bashed with a metal bollard and stabbed several times.
Hawi was convicted of murder and sentenced to 28 years in prison after a nine-month trial in 2015, but the NSW Court Of Criminal Appeal overturned his conviction on a number of grounds.
A crime scene is being set up.