PEARLAND, Texas -

A police officer stumbled upon a marijuana grow house when he spotted what he thought was a house fire, investigators said.

A Pearland police officer was patrolling the area of Northfork near Falcon Ridge about 8:30 a.m. Wednesday and smelled smoke and spotted black smoke coming from a chimney. The officer called for firefighters to go to the 3600 block of Hanover Circle.

Police said the residents admitted they burned plastic sheeting in the fireplace because they were trying to conceal the beginnings of a marijuana grow house.

About 50 marijuana plants and grow lights were found in the home, investigators said.

The home is outside Pearland's city limits, so the case was turned over to the Brazoria County Sheriff's Department. Deputies have not yet released any information about charges in the case.