Police have launched an investigation following a house fire in Merrylands overnight.
About 10.30pm, emergency services were called to a vacant home on Chester Street after reports of a fire at the location.
Officers attached to Holroyd police forced entry to the premises to conduct a search of the property and ensure no one was inside.
No one was located inside the property.
One constable suffered smoke inhalation and was taken to Westmead Hospital as a precaution.
Fire & Rescue NSW personnel extinguished the blaze a short time later.
A crime scene was established and examined by detectives and specialist forensic officers.
While the investigation remains in its early stages, police are treating the incident as suspicious.