Doug McKay, business manager of the International Brotherhood of Electrical Workers Local 258, said on Thursday that most of the workers who have been sent home with pay are linemen.
MacKay, who learned of the investigation Tuesday, said Hydro has provided few details around the inquiry.
He said he believes the internal probe centres around cases where workers upgraded transformers on buildings that may have been housing marijuana grow-ops.
McKay learned that the investigation has been going on for several months, and that BC Hydro suspects the workers may be getting "a return or something" for doing repairs on those properties.
However, McKay said he believes the employees were just doing their job.
"We make a call that we're paid to make, and that's what we do," he said in an interview.
"It's not their job to go knock on the door and say, 'Hey, have you got a grow-op?' They might get shot," he said.
McKay said he's asked Hydro to bring the allegations forward so the union can also look into the situation.
McKay said the union does not condone code-of-conduct violations, and if workers suspect that they're doing work on a property that is growing pot illegally, they should be notifying the authorities.
McKay noted the workers under investigation could also have been doing work on a place licensed by Health Canada to grow medical marijuana.
BC Hydro confirmed it is investigating a small number of employees who it said appear to have been involved in the theft of BC Hydro equipment or other activities that would constitute a violation of the company's code of conduct.
"BC Hydro and its employees take the safety, reliability and security of our system very seriously," said spokesperson Simi Heer in a written news release.
"That is why we are conducting such a thorough investigation. We need to ensure the conduct of a small number of individuals is not affecting the safety and security of the public or our employees."
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