PASSENGERS using Oyster cards to travel on the Tube and the rail network were overcharged by £60m in 2010.

Following an investigation by London Assembley Liberal Democrat member Caroline Pidgeon, Transport for London (TfL) has admitted mistakes are being made at the card’s ticket barriers.

It is blaming the extension of the Oyster card pay-as-you-go system to all of London’s 350 railway stations last year, something which Bexley Council campaigned for.

Ms Pidgeon said overcharging happens when the barriers are not working properly, have been left open or where the card is not swiped accurately.

In those circumstances, the cardholder is charged the maximum single fare of £6 regardless of what journey is made.

She now wants TfL to publish the details of how much overcharging is taking place at each Tube and railway station.