Engineer John Barrow was jailed for two years in July for sexually assaulting a 10-year-old in the 1980s.
Barrow, of Crolly in West Donegal, molested the boy after paying him to row his boat while out fishing and on another occasion when they returned from collecting turf.
The 72-year-old had been a well-respected member of the local community who held a prominent position with a local electrical firm for many years.
Early yesterday morning, three units of the fire service from Dungloe and Gaoth Dobhair rushed to the scene of the blaze at Barrow’s empty home. The fire at the former railway station house on the N56 between Loughanure and Crolly was noticed by a passerby around 8am.
The building was extensively damaged. It is understood that there was no-one in the house at the time.
The same building was gutted in a fire 30 years ago.
Barrow is in jail following his trial at Letterkenny Circuit Court in July.
A full investigation into the cause of the blaze has been launched.
It is understood Barrow has been told about the incident by prison authorities.
He is now four months into a two-year sentence for his sex crimes.