A Hamilton couple has been arrested after a fire at a marijuana grow-op on Wilson Street, police say.

The fire at 412 Wilson St., near Tisdale Avenue, started around 11:30 Thursday night, said Dave Christopher, spokesperson for the Hamilton fire department.

Christopher said crews worked well into the night.

"It's an older house and there were a number of different materials in the roof," he said. "The fire was knocked down within an hour, but the crew was working on hot spots until 4:30 in the morning."

Christopher said the fire originated in an attached garage.

Police discovered a marijuana grow-op in the basement.

The Hamilton fire department has been in touch with the owner, who told them he visited the property a week ago and the home and garage were both secure.

The Ontario Fire Marshal's office and a Hamilton police arson investigator will be at the scene Friday morning.