The 17-year-old was spotted riding on the roof of the city-bound train shortly before he was electrocuted at Caulfield train station just before 11pm.

Police said the teenager, from Camberwell, is believed to have come into contact with live wires on the Pakenham line train.

The train driver immediately stopped and police and paramedics were called to the scene.

Ambulance Victoria spokeswoman Susannah Wilson said paramedics climbed to the top of the train to assess the situation.

However they had to wait until power was isolated before they could attempt to treat him.

‘‘The 17-year-old was on top of the train. Unfortunately he was in quite a dangerous position and they had difficulty reaching him to begin with unfortunately,’’ Ms Wilson said.

The teenager died at the scene.

On a Facebook page dedicated to train surfing, the teen wrote last year: ‘‘ I am the kelly slater of train surfing’’.

The Facebook page, promoting the dangerous sport, says train surfing ‘‘provides an alternative to staring at other commuter’s gloomy faces’’.

‘‘It is a distraction from all related rush hour discomforts and the feeling being crammed onto a carriage. The thrill is surfing as many stations as you can Record your experiences and achievements here for others to admire and challenge. If you dare.... try it... why don’t you surf your train TODAY.’’

Facebook tributes are pouring in for the victim, who has been remembered as a fun-loving teenager.

‘‘You were such a great kid who didn’t deserve for his life to be cut short like this. You will be forever remembered and missed,’’ one person wrote.

Police are speaking to witnesses to determine the teen’s movements in the lead-up to the accident.

It was unclear if he was train surfing on his own at the time.

Last year, three teenagers who were photographed train surfing in Melbourne’s south-east were labelled "stupid" by authorities, who warned they were dicing with death.