A man is in a critical condition in a Melbourne hospital after swallowing hydrochloric acid when he was allegedly caught trying to steal an automatic teller machine (ATM) with a forklift on Monday.

Police told The Age newspaper that the man was discovered by security guards attempting to remove an ATM from The Glen shopping centre about 10pm.

The man tried to escape on the forklift but, when stopped by the guards, swallowed hydrochloric acid.