WINTHROP – Two men and a woman were arrested Tuesday, charged with maintaining a marijuana growing operation one veteran cop called the biggest he had ever seen.

Mark Steele, 41, Carlene Steele, 45, and Thomas Milo Johnson, 52, each was charged with aggravated trafficking in marijuana.

Police seized at least 400 pot plants and 10 pounds of processed marijuana when they raided a home at 37 Beechwood Road, investigators said. Police also confiscated $17,000 they believe was the result of drug sales.

Local, state and county officials went to the Steele home with a warrant Tuesday afternoon following an investigation into drug trafficking there.

Police used a Kennebec County drug sniffing dog to assist with a search of the house. However, locating the marijuana did not prove difficult – the grow operation was found in the daylight basement of the house, with one of the suspects tending to the plants, according to police.

“This is the biggest inside grow operation that I have ever seen in my 32 years of law enforcement experience,” said Winthrop police Chief Joseph E. Young. “The smell of marijuana was so strong that you could actually smell it from outside the house.”

When police and drug agents searched the home, they found a 20-year-old woman sleeping in an upstairs bedroom, officials said. She was not charged.

Investigators said Johnson was tending to the pot plants when police burst in. The Steeles and Johnson were taken to the Kennebec County Jail where they were booked and later released on bail.

Johnson does not live with the Steeles but is a Winthrop resident, police said.

Chief Young credited Winthrop police Officer Peter Struck with initiating and continuing the investigation on Tuesday.

mlaflamme@sunjournal.com