When investigators with the Dakota County Drug Task Force searched Scott B. Cunningham's house in Inver Grove Heights on Nov. 4, they uncovered about 14 1/2 pounds of marijuana, as well as drug paraphernalia, handguns, rifles and ammunition, according to court documents.

Then, about three weeks later, the Sheriff's Office got an anonymous tip: Did you know there was a secret room at that house where more drugs were stashed? When investigators searched the home again Wednesday, they found that secret room, hidden behind a false wall.

They also found another 377 pounds of marijuana, the documents said. It was one of the largest, if not the largest, marijuana bust in Dakota County. Last year, for example, the Drug Task Force seized about 47 pounds.

Cunningham, 42, the homeowner; Brian L. Speldrick, 52; Holly J. Swenson, 28, of Rosemount, and Jerilyn Reis, 41, of Kiester, were charged Friday in Dakota County District Court with first-degree possession and first-degree possession with intent to distribute. The former three are being held in the Dakota County jail; a warrant has been issued for the arrest of Reis.

The criminal complaints said investigators first went to Cunningham's home in the 9200 block of Inver Grove Trail about 7 p.m. Nov. 4. There were no adults in the house at the time, but about 12 juveniles were there. Reis was found in the garage. Cunningham returned home while investigators were there.

Items seized in that first search included drug paraphernalia found in the garage, a bucket with a "green leafy substance" in the woods, plastic tubs with marijuana in the trunk of a car and marijuana plants outside.

On Nov. 28, an anonymous tipster called and referred to "the bust" a few weeks earlier. The tipster said a secret room concealed by a false wall contained even more marijuana and hadn't been found during the first search. The tipster described the room as "dirty" and an "animal room," the complaints said.

Investigators searched the house again Wednesday morning and, this time, found that secret room. It was filled, in places to the ceiling, with 72 30-gallon plastic tubs full of marijuana. In all, they found more than 391 pounds of marijuana, with a street value of more than $1 million, authorities said.

Cunningham and Swenson, his girlfriend, were arrested at the house. Speldrick was arrested in the garage. Cunningham is being held in lieu of $500,000 bail; Swenson and Speldrick each had bail set Friday at $250,000.

In March 2010, police seized 927 high-grade marijuana plants and 22 pounds of processed marijuana in St. Louis and Carleton counties. Those drugs also had a street value of more than $1 million.

Pat Pheifer • 612-673-7252