Significant damage was caused to a house in Braddon early on Monday morning that has been deemed suspicious following an examination of the scene.

Police say no one was injured in the blaze, which was well alight when emergency crews arrived at the house on Ijong Street around 5.20am.

Police want to speak to anyone who witnessed suspicious activity in the vicinity of Ijong Street before 5.20am or who may have dash-cam footage from the area before or during the fire.

Call 1800 333000 or via the Crime Stoppers ACT website.