Alabama State Fire Marshal Ed Paulk said in a release Friday that investigators determined the December 23 blaze was a product of arson, per the Associated Press.
McClain had been trying to sell the brick mansion for $1.5 million at the time of the fire.
Investigators did not indicate any specific reasons for labeling the inferno as arson. However, authorities have said the fire was suspicious because the house was unoccupied and expensive. Additionally, a vehicle was seen speeding away from the scene, per the AP.
No arrests have been made, according to Paulk.