This is the moment a train driver shares a penchant for pornography with passengers via the train's tannoy speaker system.

Passengers on a South Western Railway train approaching Clapham Junction from Wandsworth Town at 11.39am on May 10 were treated to moans and groans played through speakers usually used to announce upcoming station stops.

The driver reportedly had apologised for a delay as the train had stopped outside the scheduled station.

Apparently the porn-lover forgot to turn off the tannoy system and went about getting their daily dose of the dirty material, unknowingly sharing the salacious sounds with all the passengers on the train.

Footage shows a train carriage in which pornographic sounds are being heard through speakers. Other passengers sitting across from the filmer laugh and cover their face as the sounds fill the carriage.

The voice heard in the material is male and there is some profanity.