A train driver appears to have accidentally played a porn soundtrack over his tannoy system.

Passenger Paul Brunton posted a video to Twitter recorded on a Wandsworth-to-Clapham train on Friday morning.

A series of sighs and moans can be heard as those on board try and suppress giggles, with one woman asking: “Is that coming from the driver?”

South Western Railway (SWR) has apologised and said it was investigating the incident.

Brunton’s clip, with the caption “my tube driver casually watching porn whilst leaving the tannoy system on…” has been retweeted over 13,000 times, prompting over a thousand replies.

It was later retweeted tagging TfL who replied saying “thankfully not one of our drivers”.