Man robbed at knifepoint in Sydney

A knife-wielding thief is on the run after robbing a man of his wallet and cash in a Sydney street.

The 33-year-old victim was approaching a staircase to access the Western Distributor walkway at Pyrmont about 4.15am on Monday when a man threatened him with a knife and demanded his wallet.

The robber then fled back toward Pyrmont after the victim complied.

Detectives have released CCTV footage of a man in the area at the time of the robbery.