The man told police that he had attempted to burn toilet paper used after he defecated off a forest trail in a nature park but quickly sparked a blaze.
“He said that it was an accident caused when sparks from the burning toilet paper caught dry vegetation,” said a source from the investigation, as reported La Razon.
The unnamed man, who reportedly lives in a cave on the island, was arrested by a Civil Guard patrol who discovered him walking along the road as they went to the scene once the forest fire alarm was raised.
The fire claimed the life of a 54-year-old official working for the Canary Islands Environmental Department on Thursday morning as teams battled to control the flames.
He was named as Francisco José Santana, father of five from Telde.
Some 700 residents were evacuated from their homes as a precaution as the blaze threatened to engulf residential areas around the town of El Paso on the western-most isle of the archipelago.
The inferno had already destroyed an estimated 1,000 hectares by Thursday afternoon as firefighting teams battled to bring it under control.