BC Hydro is investigating more than a dozen employees for their possible involvement in supplying power to marijuana grow ops, CTV News has learned.

A union official confirms 18 transmission line workers have already been questioned by BC Hydro’s security division, and more interviews are being conducted on Thursday.

The employees are being asked about hydro bypasses found at illegal grow ops and heavy increases to transformers feeding licensed medical marijuana grow ops, said Doug McKay, business manager for the International Brotherhood of Electrical Workers.

BC Hydro issued a statement Wednesday confirming a probe is underway into equipment theft and other unspecified misconduct.

“We are conducting a thorough, internal investigation into the conduct of a small number of employees who appear to have been involved in the theft of BC Hydro equipment or other activities that would constitute a violation of our Code of Conduct,” the company said.

“This is an internal personnel matter at the moment and we cannot provide further information at this time.”

McKay said some line workers were also questioned about calls they’d made on company phones to particular individuals, though he couldn’t say whether the recipients are suspected members of an organized crime group.

The line workers coming under scrutiny are from cities across B.C., including Prince George, Westbank, Campbell River, Surrey and Coquitlam.

The investigation appears to have started eight months ago, though the union was only notified by BC Hydro vice president of transmission and distribution Greg Reimer on Monday.

The union said some hydro employees have already been sent home with pay.

CTV News contacted the RCMP to comment on the investigation but has yet to receive a response.

With a report from CTV British Columbia’s Rob Brown