A man has died after he was stabbed on a popular South Yarra entertainment strip early on Sunday.

The man, believed to be in his 30s, was found with life-threatening injuries on a Chapel Street footpath, near Oxford Street, about 5.15am.

He was taken to hospital in a critical condition but died soon after.

A police spokeswoman said it was not known how long the man had been lying on the path before he was found by a passer-by.

Chapel Street remained closed between Toorak Road and Oxford Street on Sunday morning while homicide squad detectives investigated.

Detectives have appealed for information from anyone who was in Chapel Street, particularly down the Toorak Road end, who saw a man lying on the path or any suspicious behaviour.

Investigators have also asked for any dashcam or CCTV footage from the area.

Anyone with information should contact Crime Stoppers on 1800 333 or at www.crimestoppersvic.com.au