Man shot dead at Sydney's Bondi Junction in day ambush

He has not been formally identified but media reports have named him as a notorious Sydney underworld drug lord.

Roads surrounding the scene have been closed down and people are being told to stay away from the crime scene.

"Police believe a burnt-out Porsche located on James Street, Bondi Junction, about the same time, is linked to the shooting," NSW Police said in a statement.

Detectives are also investigating whether a second torched car - a Holden Commodore found on Cook Lane, Zetland - is linked to the shooting.

Three crime scenes have been established.