MoD computer hard drive missing
An investigation is under way into the disappearance of a computer hard drive containing the personal details of about 100,000 of the Armed Forces.
The information was being held by EDS, which is the Ministry of Defence's main IT contractor.
The MoD said the portable hard drive went missing on Wednesday during a priority audit carried out by EDS.
It is thought to contain more than 1.5m pieces of information, including the details of 600,000 potential recruits.
The BBC's Andy Moore said the incident was one of the most serious data losses for the MoD.
There is also said to be a small amount of information about bank details. It contains details of passport numbers, addresses, dates of birth, driving licence details and telephone numbers.
MoD police are investigating the drive's whereabouts, but it is not yet known whether or not it was stolen. It is understood the drive was not encrypted.
The missing drive is the latest information security breach to hit the MoD.
In July officials revealed 658 MoD laptops had been stolen over the past four years and 26 portable memory sticks containing classified information had been either stolen or misplaced since January
