Prosecutors say the oldest member of a British jewel theft gang used another person's free senior citizen's transport card to get a bus to the heist.

They said Monday they believe 76-year-old Brian Reader used a "Freedom Pass" given to senior citizens to get to the Hatton Garden diamond district.

Detectives said the free transport card Reader used was in the name of T. McCarthy, not Reader.

Reader and three others have pleaded guilty to involvement in the 14 million pound ($21 million) heist earlier this year. Prosecutors say it is the largest burglary in English history.

Four other men are on trial for their roles in the heist, which involved drilling into a vault to gain access to safe-deposit boxes containing jewelry and cash.