A man's body has been found in a charity clothing bin in Sydney's inner south after a passing motorist saw his legs protruding from the bin early on Wednesday.

Inspector Sam Crisafulli, from Redfern police station, said police were called to the grisly scene on the corner of Dalmeny Avenue and Galara Street in Rosebery about 5am.

"He was deceased when police arrived," Inspector Crisafulli said. "It's too early at this stage to be able to say what the cause of death was.

"Clearly you could see part of his body from the outside because that's how the person who saw him knew he was there."