A firefighter attempts to extinguish a hot spot in the forest northwest of Lillooet, B.C., earlier this month. (CBC)

Fifty forest firefighters battling the Tyaughton Lake fire in the mountains of southwestern B.C have been dismissed for alleged safety violations and illegal drug use, according to the B.C. government.

Pat Bell, B.C.'s minister of Forests and Range, told CBC News on Monday the workers were dismissed because the companies did not provide enough "danger tree assessors," who monitor the safety of trees in wildfire situations.

The required ratio is one assessor for every five firefighters.

Bell also confirmed three workers were let go because they had allegedly been "using a banned substance," but would not say what kind of substance or under what circumstances they were used. Bell would not release which company the alleged drug users worked for, but said drug use would affect safety on the site.

"You cannot have someone on a fire line who has the potential to have their judgment impaired. We take anything like that very seriously — people's lives are at stake — so we have a zero tolerance policy on that issue," Bell said.

RCMP in Lillooet are investigating the allegations of drug use.

According to Vivian Thomas, a public relations representative from the B.C. Ministry of Forest and Range, the crews were asked to provide safety documentation on June 16 — the day after they began working on the fire — by noon on June 17.

Company disputes government allegations

Thomas named Grayco, Frontline and Firestorm as the three B.C. companies that were asked for the paperwork. But many details about the dismissals remained unclear, including whether the workers were fired or the companies' contracts were cancelled.

Firestorm owner Bob Swart has already disputed the government claims. He told CBC News on Monday his company did provide the documentation and there were no safety issues with his crew, but 10 firefighters were let go from the Tyaughton Lake fire because of what he called "downsizing."

Officials with the ministry said the number of workers on the fire was reduced because the fire was largely under control, but maintained all 50 workers in question were let go because of the safety concerns.

No one at the company office of Grayco, a Kamloops-based company, would answer CBC News calls on Monday.

Officials at the Squamish-Lillooet Regional District who are monitoring the fire northwest of Lillooet said they were not aware of the dismissals. They said the Tyaughton Lake fire is under control and the crews that remain are "mopping up."