Derelict house destroyed in Vic fire

Investigators are at the scene of the third suspicious fire in weeks at a derelict house in Melbourne.

The two-storey house in St Kilda has been severely damaged by the latest fire, believed to have started on the internal staircase.

Metropolitan Fire Brigade commander Frank Stockton said it took an hour to bring the blaze under control.

Crews remain at the scene to monitor and extinguish the fire.