Homicide detectives are seeking public assistance as they investigate the death of a sex worker in Melbourne's beach suburb of St Kilda.

The body of the 40-year-old woman was found in a van yesterday afternoon on Greeves Street, a part of the area's red-light district.

Police believe the van had been parked in the area for a month

They also believe the woman had been living in it and was killed inside.

She was found about 3pm with upper-body and facial injuries.

The woman's boyfriend discovered her body and a post-mortem examination will be conducted to determine the exact cause of her death.

Detective Inspector John Potter says the community of sex workers in the area may have information about the woman who went by the name 'Kelly'.

"There's quite a community in that environment in St Kilda and there will be street talk about what went on and who was responsible," he said.