An elderly man has died after being struck by a train as he crossed a railway line in the Melbourne bayside suburb of Brighton.

Police said the man had already started to cross the tracks when the signals began operating at the Middle Brighton Railway Station just after 10:00pm.

"Investigators understand the man was unable to complete crossing before being struck by an unoccupied, low-speed city-bound train," a police statement said.

The man died at the scene.

Investigators are preparing a report for the coroner.

Anyone with information is asked to contact Crime Stoppers.