A train driver was left red-faced after mistakenly announcing she had run a red light over the tannoy.

Passengers on board the packed Southern 6.47pm London to Hastings service on Tuesday were more than a bit bemused when they heard the driver telling a colleague not to tell the passengers but she had stopped because she had run through a red signal.

Minutes later there was a second announcement from the guard informing passengers the train was being held at a signal just outside Streatham Common station.

But commuters were not impressed when they overheard the driver say she had not been given permission to continue the journey.

Instead the guard told passengers the train would terminate at Streatham Common because of a fault.

Southern has apologised to passengers saying staff had tried to deal with the incident without "causing alarm".

A full investigation into what happened is now underway.

A spokesman for the rail company said: "Southern wants to assure all those passengers on board that they were safe at all times and that all the correct procedures were carried out following the incident.

"We understand that some passengers were concerned about the conversation overheard between the driver and the conductor.

"Clearly, as all the passengers were safe our staff did not wish to cause alarm and wanted to deal with the situation in a way that would allow passengers to continue with their journeys as quickly as possible.

A full investigation of the incident is already underway.

"Southern are very sorry for any trouble or confusion caused to passengers."