A man and a woman in their 50s have been arrested on suspicion of growing cannabis after equipment and plants were found during a house fire.
Fire crews were called to a semi-detached house which was alight in Fegg Hayes, Stoke-on-Trent, Staffordshire.
The fire began at about 0200 BST and badly damaged the roof. The occupant escaped and no-one was hurt.
Police and fire crews are investigating whether heating equipment for the plants may have started the fire.
A man was arrested shortly after in a nearby property where more cultivating equipment was found.
Ch Insp Peter Hall, from Staffordshire Police, said "It's too early to confirm that the fire was caused by the growing of the plants, but it is one of the lines of enquiries currently under investigation."