A man whose son wants state permission to open four medical marijuana dispensaries is going to jail after pleading guilty to charges of growing and selling pot illegally.

Robert Sirois of Farmington, who was 56 when arrested Sept. 15, was spotted walking into a house in Industry with a large bag full of marijuana.

Agents with the Maine Drug Enforcement Agency said they believed he had been harvesting marijuana that was growing in the area. Inside the building, police found 40 pounds of marijuana and 125 plants growing in the basement.

Police said the seized drugs would have been worth $200,000 if sold on the street.

Sirois is the father of Lucas Sirois, the Farmington contractor who has applied to operate four of the state’s eight medical marijuana dispensaries, Baril said. Lucas Sirois has never been arrested by MDEA, Baril said.

The elder Sirois pled guilty to felony trafficking in marijuana and felony cultivation of marijuana, said Gerry Baril, MDEA supervisor for central Maine. A Franklin County Superior Court judge sentenced him to five years in prison, with all but nine months suspended, three years probation and a $20,000 fine.

A co-defendant, Charles Correll, who owned the house where the arrest occurred, was convicted of cultivating marijuana and given a three-year suspended sentence and fined $1,500, authorities said.

Asked whether Robert Sirois’ conviction could affect his son’s application, Catherine Cobb, director of the Department of Health and Human Services’ division of Licensing & Regulatory Services, said she could not comment on specific applications. She did say the law prohibits the staff, officers and directors of a dispensary and caregivers from having a disqualifying drug offense.

Lucas Sirois has said he is planning to pursue the business opportunity with his wife, Lisa. Calls to Lucas Sirois’ business and cell phone were not returned by press time.