A passenger has been filmed sliding naked down the centre of a Melbourne train.

A number of videos, posted on a Facebook page dedicated to a Melbourne train line, show the naked man making his way up the carriage, before he turns around, takes a run up and launches onto his stomach sliding a number of metres down the centre of the carriage.

The centre of the train looks to have been covered in a liquid.

Metro trains condemned the behavior. (9News)

The man slid for a number metres on his stomach. (9News)

It is believed the incident took place just after 9.30 pm yesterday.

A spokesperson for Metro condemned the behaviour and urged passengers to contact Metro staff or police straight away if they witness similar behaviour.

“Passenger safety is Metro’s number one priority and this type of behaviour is completely unacceptable on public transport,” the statement read.

“If passengers witness anything of this nature on board a train, we urge them to press the emergency call button to alert Metro staff or to call police.