Around 45,000 people have benefitted from free travel on the Barking to Gospel Oak line - but even more could be entitled to refunds.

That's according to Transport for London (TfL), which has revealed that around £175,000 has already been paid back to customers who travelled between August 31 and September 7.

It believes that around 2,000 more people could be eligible for a refund but are unable to receive one because they are not touching out to complete the journey. The majority of these are thought to be Travelcard holders.

TfL is now calling on passengers to make sure they tap their Oyster or contactless card correctly at the start and end of every journey in order to get the refund.

Rory O'Neill, TfL's general manager of London Overground, said: "Our free travel month on the Gospel Oak to Barking line is to show appreciation for our regular customers and an invitation for those from further afield to come and explore the many interesting places we have in this part of north London.

"All journeys made on the line during this month are refunded, but we need customers to make sure they are touching in and out when using Oyster or contactless, even if they have a Travelcard, so we are able to calculate and process their refund as quickly as possible."

Journeys between August 31 and October 1 are free as compensation for the months of disruption caused during the electrification process.

The line was initially closed for eight months from June 2016 for work to be carried out, but some materials were incorrectly designed and others delivered late. This led to another two month closure at the end of 2017 - but then the new trains weren't ready.

The problems with the trains continued into this year, beyond when leases on some of the old stock ran out, meaning a reduced timetable had to be implemented.

The new trains are now running as they ought to, meaning the free travel - which will be funded by manufacturer Bombardier Transportation - can be introduced.

Refunds for Oyster and contactless card users using pay as you go, weekly or monthly Travelcards are automatically processed within two weeks of travelling.

Longer Oyster Travelcard users will need an online account to get the refund and paper ticket holders can submit a refund claim via TfL's customer services by November 30.