The London Ambulance Service (LAS) has revealed that it was forced to use pens and paper to record calls after its computer systems crashed on Wednesday.

An LAS spokeswoman told the Guardian newspaper that the LAS used paper documents while the computers were out of action, writing call details down and passing those details on to ambulance crews by radio. "At all times during this process our priority was to answer all incoming 999 calls, and get an appropriate response to those patients with the most serious illnesses and injuries," she said.

The news was shortly by a report form National Audit Office, which highlighted the need for improvements in the treatment of data collected by the London ambulance service.

"The emergency services must now quickly develop procedures for collecting and sharing information across organisations to measure performance. The key is for data systems that can link different organisations," the report said.

The LAS agreed it could be more efficient and said it was examining its practices.