A missing Ministry of Defence computer hard drive may contain personal details of as many as 1.7 million people who have inquired about joining the armed forces.

A missing Ministry of Defence computer hard drive may contain personal details of as many as 1.7 million people who have inquired about joining the armed forces.

Opposition parties warned that the information on the drive represented "a potential goldmine for organised crime" and could compromise national security.

When the loss of the disc from the premises of contractor EDS in Hook, Hampshire, was announced last week, it was thought that it carried the names, addresses, passport numbers, dates of birth, next-of-kin and driving licence details of up to 100,000 Army, Navy and RAF personnel.

But in a written statement to parliament, Armed Forces Minister Bob Ainsworth said: "The hard drive had been used with the TAFMIS recruitment system and may, in the worst case, contain details relating to 1.7 million individuals who have enquired about joining the Armed Forces."

For casual inquirers, only name and contact numbers are likely to have been recorded, said Mr Ainsworth, but for those who applied to join up, data on the drive could include next of kin, passport and National Insurance numbers, drivers' licence and bank details and NHS numbers.

It was unlikely that the details on the hard drive were encrypted for security.

Meanwhile rail union, the Transport Salaried Staff Association, called yesterday for an urgent inquiry after a laptop with details of 150,000 workers in the industry was stolen.

The computer was taken several weeks ago from an employee of Deloitte which until recently worked for railway pension scheme administrators. The union was only told in the past few days.

The company said the laptop did not hold bank account details.