Victoria’s Metro Trains has been charged by the state’s transport safety authority for breaching safety obligations.

The charges come as a result of the death of teenager Mitchell Callaghan, who fell from a platform as his friends held open a train's doors.

Close to midnight on February 22, 2014, 18-year-old Callaghan died while trying to get onto a train departing from Heyington Railway Station in Toorak.

Transport Safety Victoria charged Metro with failing to ensure the safety of rail infrastructure, specifically the gap between the platform and the train.

It is also accused of failing to ensure the safety of its rolling stock in relation to the train doors.

“As Victoria's transport safety regulator, my primary objective is to independently seek the highest transport safety standards that are reasonably practicable, and the filing of these charges is consistent with that purpose,” Transport Safety Victoria director David Hourigan said in a statement.

“This has been a long and thorough investigation and I am satisfied that taking court action in this case is in the public interest.”

The state watchdog investigated the incident under a Victorian law that existed at the time, but Victoria's heavy rail operations are now the responsibly of Office of the National Rail Safety Regulator.