Hundreds of inaccurate patient records have been created every day due to a fault on the controversial new NHS computer system, it has been claimed.

The problem affects patients in Greater Manchester who have hospital appointments booked via the online system.

NHS Connecting for Health, which is overseeing the £12.4 billion (€18.2 billion) upgrade of the patient records system, stressed the fault would have no impact on patient care.

An article in Computer Weekly magazine revealed the problem arose after computer experts installed a software upgrade.

This caused the computer to automatically create a new blank patient record without checking if one already exists raising fears doctors may be presented with the wrong information.

A spokesman for NHS Connecting for Health said the problem was expected to be fixed in the next few weeks.

He said: "Although comprehensive testing is undertaken prior to the upgrades taking place, it is not unusual for these kinds of upgrades to identify teething problems in the early stages following implementation.

"We estimate that around 400 duplicate patient records might have been created each day. However, the system is being continually monitored throughout each day and where a duplicate is identified data is being merged to form one single record for each patient."

He added: "Prior to the application of the permanent fix, an interim solution has been put in place to identify the duplicate records and correct them. This has now been put in place with the full agreement of those organisations affected and will have minimal impact on the users of the system and no impact on the delivery of patient care."

Among the places affected by the problem are the University Hospital of South Manchester Foundation Trust and PCT Clinical Assessment Centres in Greater Manchester.