LONDON – The British government said Monday it has found no evidence that patients were put at risk when hundreds of thousands of confidential medical documents were mislaid over a five-year period.

Health Secretary Jeremy Hunt told lawmakers that 708,000 pieces of correspondence between hospitals and family doctors were mistakenly stored in a warehouse by subcontractor Shared Business Services between 2011 and 2016.

The Guardian newspaper reported that about 200,000 of the letters were change-of-address forms. The remaining 500,000 contained medical information including blood test results, cancer diagnoses and treatment plans.

Hunt said “no patient data was lost.”

He said “every single piece of correspondence has been assessed,” and “there is no evidence so far that any patient safety has been put at risk,” though some of the information is undergoing a second check.

Opposition politicians demanded to know how the mix-up happened. Labour Party health spokesman Jonathan Ashworth said it was an “absolute scandal,” and Liberal Democrat leader Tim Farron called the episode “a staggering loss of personal, private data.”

SBS is co-owned by Britain’s Department of Health and French company Sopra Steria.