I am answering this question on behalf on the Crown Prosecution Service, Serious Fraud Office, Revenue and Customs Prosecutions office, HMCPS Inspectorate and the Attorney-General's office.
The definition of “found to have been in breach” can be broad. Depending on their nature, breaches by Government Departments of the Data Protection Act can be dealt with by the Information Commissioner, the courts or by Departments at an informal local level. The information requested is not held centrally and could be provided only at disproportionate cost.