Three cars torched in suspicious fire in South Wentworthville in Sydney's west

Multiple cars have gone up in flames following a suspicious fire in Sydney's west that is now under investigation.

Emergency services were called to the scene on Alto Street in South Wentworthville about 12.20am on Wednesday after reports of a fire.

Police officers arrived to find three vehicles, a black Mercedes sedan and two Toyota utilities "well alight", a NSW Police spokesperson said.

Firefighters put out the fire, but all three vehicles were destroyed in the blaze.

There was no further damage to surrounding properties, according to police.

The fire is being treated as suspicious.

A crime scene has since been set up and and a probe into the incident is underway.

Inquiries are ongoing.