Exclusive: Guardian investigation finds data from flagship medical research leaked dozens of times

Confidential health data has been exposed online on dozens of occasions, a Guardian investigation can reveal, raising questions about the safeguarding of patient records by one of the UK’s flagship medical research projects.

UK Biobank, which holds the medical records of 500,000 British volunteers, is one of the world’s most comprehensive stores of health information and is credited with driving breakthroughs in cancer, dementia and diabetes research. But scientists approved to access Biobank’s sensitive data appear to have sometimes been cavalier about its security.