A Ministry of Justice spokesman said: "We treat the security of information very seriously and took immediate steps to recover the data as soon as the loss was reported to ensure that it went no further.
"These types of incidents are extremely rare but this does not mean that we are complacent.
"A thorough investigation was held by the prison who immediately altered their procedures, and further changes were implemented across the prison estate."
More top news
Rain will ease across central Scotland this morning but it will continue throughout the day across much of Scotland and the north.
An orangutan who has lived in a zoo for the past 20 years, can be granted basic human rights, a court in Argentina has ruled.
Socialite Tara Palmer-Tomkinson has been cautioned by police after a 'disturbance' at Heathrow Airport.