Victorian man dies in suspicious house fire

A man has died in a suspicious house fire in Victoria's northwest.

Police and fire crews were called to the blaze in Red Cliffs, near Mildura, about 11.15pm on Sunday.

The 52-year-old man's body was later found inside his completely destroyed home.

Arson detectives were at the property on Monday to investigate the cause of the fire, Detective Inspector Chris Murray said.

"We believe that it was deliberate," he told reporters.

"We have one individual currently assisting us with their inquiries."

Det Insp Murray said it was too early to say whether the person in custody and the deceased knew each other.

"I'm not able to go into specific details at this early stage in the investigation but we're very confident this was a deliberate act," he said.

He encouraged anyone with information to contact Crime Stoppers on 1800 333 000.