AUBURN, Maine — The state is continuing its investigation of a medical marijuana cultivation operation in Auburn.

The facility is owned by Wellness Connection of Maine and is at 33 Omni Circle, near the Lewiston-Auburn Municipal Airport. Wellness Connection owns four of the eight medical marijuana dispensaries in Maine, making it the largest distributor in the state. Workers at the Omni Circle location cultivated marijuana but did not dispense it to patients.

Wellness Connection’s four dispensaries are in Portland, Hallowell, Brewer and Thomaston. It does not own Remedy Compassion Center, a medical marijuana dispensary on Center Street in Auburn.

DHHS spokesman John Martins confirmed the investigation which began last week, but declined to say more because the investigation is ongoing. It is unclear why the department, which licenses and oversees medical marijuana operations, is looking into the facility.

Maine’s medical marijuana regulations fill more than 70 pages and include several stipulations for cultivators, including that they cannot use pesticides, they must maintain strict security measures and only those authorized by law may be allowed to enter the facility.

Becky DeKeuster, executive director of Wellness Connection, declined to say much about the investigation until the state releases its findings.

“Inspections are standard in any highly regulated business such as ours, and this is a step toward normalized business operations in an industry that has been largely self-regulated until recently,” she wrote in an email.

Maine voters legalized medical marijuana in 1999 and approved a law creating marijuana dispensaries in 2009. Martins at DHHS and the legislative liaison for the Medical Marijuana Caregivers of Maine, an association of growers and providers, said this is the first such investigation they are aware of.

City permit records show Wellness Connection began working out of the Omni Circle building last May. It initially received building, plumbing and electrical permits for 4,500 square feet, followed by permits to renovate over 20,000 square feet in August. Because that area of Auburn was already an industrial zone, no other city permissions were required.

“Considering that it’s a legal use within the state, we didn’t look at it any differently than any other kind of production or manufacturing-type use,” said Eric Cousens, director of planning and permitting. “They could have grown tomatoes or built Legos there, and it would have been the same thing.”

Wellness Connection’s four dispensaries were closed last week. Martins said the closures had nothing to do with the DHHS investigation.

DeKeuster said the closures “were the result of a combination of the inspections and some technical difficulties that we’re having in implementing our inventory tracking system upgrade and then our new harvest.”

All Wellness Connection sites have since reopened.