Body found in burning Sydney house

A body has been discovered inside a burning house.

Firefighters found the body as they battled a blaze in the western Sydney home on Kalang Avenue, St Marys.

The fire started about 7am and continues to burn.

"We still have crews on scene and the fire is still an active fire, and crews will be on scene for quite a while," a FRNSW spokesman said.

No other details on the fatality were available, he said.

It's not immediately known how the person died.