An exploding dog has been blamed for an overheating chimney which sparked an alert at a Darwin pet crematorium last night.

Emergency services were called to the crematorium after a passing motorist reported the premises were on fire.

Three fire trucks and a police car investigated a reported 'red glow' coming from the chimney flue.

Authorities confirmed flames were coming out of the flue and called the proprietor.

He revealed that a frozen dead dog in the furnace was the cause of the overheating chimney, as frozen dogs sometimes explode when cremated.