A child has died and a man has been left seriously injured after an early morning house fire in Melbourne’s south-west.

Emergency services were called to Newbury Street in Werribee just after midnight on Monday.

Crews extinguished the blaze before finding a child deceased inside, Victoria police said.

A male resident was taken to hospital with serious injuries.

Fire crews arrived at the scene within three minutes, by which time the single-storey brick home was fully alight, Fire Rescue Victoria said.

It took about an hour for 40 firefighters to bring the blaze under control.

The circumstances surrounding the fire were being investigated but it was not being treated as suspicious, police said.

An arson chemist will attend the scene.

ABC has reported firefighters were told children were trapped inside the burning house but some managed to get out.

Peer support and counselling have been made available to first responders.