MUMBAI, May 17 -- An FIR was registered on Friday against a Kolkata-based railway equipment supplier for allegedly supplying counterfeit and expired circuit breakers that failed during a fire incident aboard the Mumbai-Firozpur Punjab Mail in March. Police said that the accused firm, Aspee Sales Corporation, had supplied 325 Motor Protection Circuit Breakers (MPCB) to the railways for Rs.4 lakh after winning an online tender floated in November 2025. Some of the devices were installed in a coach later attached to the Punjab Mail. On March 7, while the train was travelling from Mumbai to Firozpur, smoke emanated from one of the coaches near Firozpur, hinting at a fire-like situation. "The MPCB installed in the coach failed to trip despite a high-voltage current, resulting in the incident," a police officer said. It was found that some of the MPCBs were counterfeit. The original manufacturer informed the railways that Aspee Sales Corporation was not its authorised dealer and that the supplied product had expired, police said....