BAE Systems has said that it is "concerned" to hear of the data loss, but that it is "a matter for the Serious Fraud Office".
The defence giant also confirmed in a statement that the material was not sent to a current or former employee of the company.
We were concerned to hear of this unfortunate incident but understand it has now been dealt with by the relevant authorities. Ultimately, this is a matter for the SFO and as far as BAE Systems is concernedit is now closed.
More top news
Strong winds and showers look set to hit the UK this weekend as wind speeds of up to 70mph are expected in parts of the UK.
A police constable has been jailed after admitting arranging to have sex with a 15-year-old runway while investigating her disappearance.
Five-year-old Isis was told she could not have her name printed on a personalised Nutella jar as it may be "viewed as inappropriate".