The information commissioner has told the NHS it needs to tighten data security, after thousands of data breaches involving patients' medical records.
The data watchdog says he has taken action against 14 NHS organisations in the past six months.
Assistant information commissioner Mick Gorrill told the Independent newspaper that the data losses were "inexcusable" and had become a cause of "great concern".
Information commissioner Richard Thomas has written to the Department of Health asking for immediate improvement.
The NHS reported 140 data breaches between January and April this year - more than central government and local authorities combined.
The breaches included one instance when a memory stick containing the medical details of more than 6,000 prisoners in Preston Prison in Lancashire was lost. The data was encrypted but a note attached to the stick gave the password.