Police are renewing their appeal for information about a Richardson house fire they believe was deliberately lit in May.

Emergency services were called to the Clift Crescent home about 3am on May 31.

Police believe at least one person attended the property shortly before the fire and that three people may have been inside when it was set alight.

Investigators are urging those people, or anyone with information about the fire, to come forward.

Police have also warned people against entering the fire-damaged property, saying the building may be unstable and contain hazardous materials including asbestos.

Anyone with information is urged to contact police via the Crime Stoppers ACT website.

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