Senior police sources say Dr Vin Sein Chiang was attempting to defend himself when he was shot dead outside his Wallerfield home early this morning.
Investigators probing the matter told Guardian Media that shortly after 4 35 am, Dr Chiang, 75, had just driven his car out of the yard of his home and closed the gate when he was confronted by two men, one armed with a gun.
They say the doctor tried to defend himself with a black knife he kept in his possession but during the confrontation, he was shot. His attackers then escaped on foot.
Dr Chiang called out to his wife who was inside the house and she ran out and found him bleeding. He died a few minutes later.
The former director of the T&T Medical Board leaving for his office at the time of the incident.
Police are yet to establish a motive for the killing.