The policy states that personal information about myki customers will be handed to police when ''an authorised police officer certifies in writing that the disclosure is reasonably necessary for the enforcement of the criminal law''.

TTA chief executive Bernie Carolan said police were handed information only when justified. ''Strong privacy controls are maintained at the TTA and any release of data to, for example, the police is only granted when sufficient justification is given. Release of the data is always approved by TTA senior management,'' he said.

The reusable smartcard is microchipped and collects information on the movements of about 2.2 million public transport users, including when and where they touch on and off.

Customers who register their myki card must provide their name and either a phone number or postal or email address. Some concession card holders must provide the TTA with their residential address.

Mr Carolan said the authority had declined police requests for customer information on nine occasions, including eight times this year. He would not provide details about why the requests had been declined, saying only they did not meet the required standard.