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
The showers will be frequent, heavy and blustery with a mixture of rain and hail.
Facebook, Twitter and Google "are not simply platforms for the content that others post" because they play a role in shaping what users see.
The condition was revealed by a nine-week scan, which showed the baby's heart and part of her stomach growing outside the body.