A train driver in the United Kingdom made passengers giggle and look at each other with bewilderment after he played what sounded like audio from a pornographic clip over the loudspeaker system.

The bizarre incident came to fore after one of the passengers, Paul Brunton, tweeted a small clip of the audio that was broadcast on the Wandsworth-to-Clapham train in London recently. The tweet soon went viral with many netizens coming up with jokes and puns over the goof-up.

“My tube driver casually watching porn whilst leaving the tannoy system on…,” Brunton tweeted.

The clips showed many commuters giggling and wondering about the source of the noises.

A woman asks: ‘Is that coming from the driver?’, to which another replies: ‘No, it’s someone’s phone.’

The duo erupts into fits of laughter as the embarrassing noises continue to echo through the coach. Paul later retweeted his video and tagged Transport for London (TfL), with the caption: ‘Amazing multitasking here’. TfL responded by saying: ‘Oh dear thankfully not one of our trains or drivers’, accompanied by a crying laughing emoji.

In a statement, South Western Railways said: ‘We have a policy of blocking inappropriate material, including pornographic websites, on its onboard and station Wi-Fi services. ‘We are investigating this incident to establish how this material was broadcast on our service. ‘Today’s incident is wholly unacceptable and we apologise to customers.’