The Bank of New York Mellon Corporation has admitted to misplacing the details of 4.5 million customers, following the loss of a data tape earlier this year.

The backup tape went missing on 27 February while being transported to an off-site archive by a third-party vendor. The lost data includes the names, birthdates and social security numbers of customers of the Bank of NY Mellon and the People's United Bank in Bridgeport, Connecticut.

The bank said it believes that none of the lost data has been affected, and that it has begun contacting affected parties.