Grisly discovery of young woman's body in the water in Sydney's west.

A woman, believed to be in her 20s, has been found dead, floating in the water at Cabarita Wharf in Sydney’s inner west overnight.

Nearby neighbours reported hearing screaming and pleas for help coming from the wharf late in the evening, which triggered calls to police and other emergency services of a possible assault.

Police from the nearby Burwood Local Area Command were shortly dispatched, arriving on the scene shortly before 11.30pm.

Inner north Sydney's Cabarita Wharf. Source: Google Maps.

When they arrived, they found the woman in the water near a ferry wharf.

Sadly, NSW Ambulance Paramedics were unsuccessful in reviving the young woman and she was pronounced dead at the scene of the crime.

A 35 year-old man was arrested at the scene and was taken to Burwood Police Station for questioning.

Police said they did not know if the man and woman knew each other, or what the relationship between the two was. No charges have been laid at this time.

The man will be questioned by police later this morning.

A crime scene has been established, and the area sectioned off, with only local residents being granted access at this time.