Luxury carmaker BMW is counting the cost of a drugs bender by two technicians whose breaktime marijuana binge stopped production when they collapsed on the assembly line.

The incident happened on March 3 but has only just come to light in Germany.

Media reports said the two men - both fitters - cost the company close to £1million in lost production when they passed out at the Munich plant.

The incident happened at the BMW factory in Munich (pictured) on March 3 but the news has only just emerged in the last 24 hours (file photo)

The assembly line was idle for 40 minutes when the zonked-out duo fell unconscious on the late shift at 10.40pm.

Apparently they used their break to smoke the drug in their locker room.

Bild newspaper said it received information of the massive loss in production from company sources.

An ambulance was summoned for the two men, both Polish nationals, who worked on vehicle exhaust systems.

One had a high amount of alcohol in his blood, the other the drug amphetamine - the effects of which were both boosted with the breaktime joint.

One of them was transferred to a clinic for further treatment. BMW admitted a loss in production but claimed it was lower than in media reports.

The company said it was the first time such an incident had affected production.

One of the men has been sacked, the other relocated.