The Department of Health has been found in breach of the Data Protection Act following leaks of personal information about junior doctors, the Information Commissioner's Office said yesterday.

The breach of the Medical Training Application Service (MTAS) website occurred earlier this year during the row over doctor training.

It meant personal details relating to junior doctors, including their religious beliefs and sexual orientation, were accessible to anyone using the site.

The ICO was alerted to the breach by Channel 4 News, which reported in April that doctors were able to see the personal details of others on the site.

The Department of Health suspended the site while the allegations were investigated. The whole system was shelved in May amid calls for former health secretary Patricia Hewitt to resign.

The ICO said in a statement yesterday that it had demanded the Department of Health take action to prevent breaches happening.

Mick Gorrill, assistant commissioner at the ICO, said: "This is an unacceptable breach of security.

"Organisations must ensure that the personal information they hold on us is secure - this is an important principle of the Data Protection Act.

"Individuals must feel confident that their personal details cannot be accessed by another party. Research by the ICO shows that nine out of 10 individuals are concerned that organisations are failing to keep their information secure

so it is essential that the Department of Health takes the appropriate measures that we have outlined in order to protect individuals' personal information."

A Department of Health spokesman said: "We take data protection very seriously. Following the original security breach on the MTAS website, the department tightened its data security procedures and ensured the MTAS system was penetration and vulnerability-tested.

"We are not using a national IT system for speciality training recruitment in 2008. Deaneries will arrange their processes locally. Any future national application systems will be implemented only after careful consultation with doctors, proper piloting and rigorous security checks."