Almost £170 million remains unclaimed on disused Oyster cards, according to Transport for London.

Deposits, worth £83.2 million, and pay as you go balances of £85.6 million have been left on Oyster cards which have not been used for more than a year.

The cash pile from unused Oyster cards has been steadily growing since the start of Oyster in 2003.

A recent written Mayoral question revealed that when Boris Johnson first became Mayor in May 2008 the amounts left on dormant Oyster cards was just £4.25 million in Pay As You Go balances and £2.81 million in deposits.