BASS Coast Crime Investigation Unit are investigating a suspicious house fire this morning in Dalyston during a period of torrential rain.

Authorities were alerted to the blaze at 6.45am on June 17 with a number of local fire brigades attending, including Dalyston, Kilcunda and Wonthaggi.

It's alleged the fire was deliberately lit with the parties known to each other. 

There were no injuries to people at the address at the time; however, it's understood a cat was caught up amongst the flames and rescued by firefighters.

Anyone with information about the fire, or who might have seen suspicious activity in the area, is urged to contact Bass Coast CIU on 5671 4100.

Separately, a firefighter was injured at the scene, but the injury is understood to be unrelated to the fire.