A suspicious fire has destroyed a former service station that had been converted into a home.

Emergency services were called just after 9.15 pm on Sunday to a building on Granite Belt Dr in Cottonvale, about 3 hours southwest of Brisbane, to find the house engulfed in flames.

Twelve fire crews fought the fierce blaze from multiple fronts for over three hours.

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A large portion of the building was destroyed before the blaze was brought under control, Queensland Police said.

No one was inside at the time and no injuries have been reported.

A crime scene has been declared and investigations are ongoing.

Police urge anyone with information or dashcam footage to come forward.

Details can be reported to Policelink or anonymously via Crime Stoppers on 1800 333 000.