Published Tuesday, 19 June 2012
The fine follows a serious breach of the Data Protection Act. (© Getty)
They were discovered at the site of the former Belvoir Park Cancer Hospital in Belfast after it closed down in 2006.
Some of the files - which included sensitive information such as medical records, X-rays, lab results and staff records including unopened payslips - were stolen and posted online.
The Trust has been served with a Civil Monetary Penalty (CMP) of £225,000 over what the Information Commissioner's Office has described as a serious data breach.
"The severity of this penalty reflects the fact that this case involved the confidential and sensitive personal data of thousands of patients and staff being compromised," said Ken Macdonald, the ICO's Assistant Commissioner for Northern Ireland.
"The Trust failed to take appropriate action to keep the information secure, leaving sensitive information at a hospital site that was clearly no longer fit for purpose.
"The people involved would also have suffered additional distress as a result of the posting of this data on the Internet.
"The Trust has therefore failed significantly in its duty to its patients, and we hope that the action we've taken sets an example for all organisations that they must keep personal data secure, irrespective of where they choose to store it."
Health Minister Edwin Poots said he is "very disappointed" about what happened.
"It is money we can ill afford lose," the DUP minister told UTV.
"I did come to the Assembly last June to report that this had happened and to report also in terms of the security that was taken on it hadn't went through proper procurement exercises and indeed other problems that I had found in the Belfast Trust.
"So these are all things that we were aware of and amongst the reasons we took the Belfast Trust into special measures earlier this year."
Alliance MLA Kieran McCarthy said someone has to be made accountable.
"The failure to secure these patient records was a horrendous mistake and has now resulted in a large fine that the Belfast Health Trust can ill afford to pay," he said.
"When people are crying out for cancer drugs and other treatments and services in our health service, why was this situation allowed to happen which has led to this large fine.
"Question do remain as to who is ultimately responsible for this debacle. Who will carry the blame for this fiasco? Somebody needs to be held accountable for this incident."