Man arrested after woman’s body found in bathroom of Sydney apartment

A 20-year-old man is in custody after the discovery of a woman's body at an apartment in Sydney's west.

The man presented himself to officers at Bankstown police station shortly before 1pm after a police appeal for information on Monday morning.

Police conducted a welfare check at a unit on Pennant Hills Road at North Parramatta about 4.30pm on Sunday, after a call from concerned relatives.

Officers had to break into the unit and found the woman's body in the bathroom.

They called in specialist Hazmat officers from Fire and Rescue NSW, who spent several hours at the apartment.

"I can confirm there were chemicals found inside the bathroom of the unit [but] I can't confirm at this stage what the chemicals are," Superintendent Julie Boon said.

"The scene was very challenging for arriving police. When they did arrive and found chemicals inside the unit, they retreated."

The woman's cause of death is yet to be established but an autopsy will be completed either on Monday or Tuesday.

Police have also taken a truck from Greenacre for forensic examination as investigations in to the woman's death continue.

No charges have been laid.