An investigation is underway into a fatal house fire at Geeveston overnight.

Emergency responders were called to the property on Huon Highway about 9.30pm.

Tasmania Fire Service volunteers were first to arrive, to find the house fully engulfed by fire.

The fire took a considerable amount of time to extinguish.

Sadly, the body of a man was found deceased inside the house. The body is believed to be that of a man in his 70s, who was the sole occupant of the property.

Investigations into the cause of the fire will continue today.

A report will be prepared for the Coroner.