AMBULANCE response times were falsified in a desperate attempt to meet targets, a shocking report has revealed.

The Audit Commission found control room staff "routinely" changed computer records to improve the performance figures of the troubled former Wiltshire Ambulance Service.

Its report states a total of 594 "life-threatening" calls - known as Category A - were recorded as being reached within the critical eight-minute target, when it had taken longer for an ambulance to arrive.

A further 89 Category B "serious" calls were incorrectly logged as being dealt with within 19 minutes. The Trust's former chief executive alerted the Audit Commission to the scandal, which took place unchecked between April 2005 and July 2006.

It found data was "easy to manipulate" and staff had "both the opportunity and motive to do so."

Wiltshire Ambulance Service - which merged with trusts in Avon and Gloucestershire to become Great Western Ambulance Service in 2006 - was once named as the worst in England for its 999 response times.

The failing trust was given zero stars in government ratings, and only 54 per cent of the top priority calls were reached within eight minutes - falling far short of the 90 per cent target.

In 2004, Wiltshire County Council launched an investigation into the poor performance, and the Trust vowed to make improvements.

But auditors found staff resorted to fiddling the response times, and suggests under-pressure bosses were part of the scam.

"The public interest report recognises that in a culture where managers' jobs depend on achieving specific targets, there will be pressure to meet those targets," the report states. If the system is properly managed it can be used to monitor and improve performance as a whole. But the system can also be used to manipulate the data, rather than changing the way the service is delivered."

Appointed auditor, Richard Lott, said: "The key performance indicator for ambulance trusts is how quickly the ambulance arrives at a situation. It is crucially important the public has confidence in the integrity of the data used to produce this indicator."

The Trust has been asked to consider taking disciplinary action against staff who altered the response times, and ensure the con never happens again.

Chief Executive of Great Western Ambulance Service, Tim Lynch, said: "The report dates back to 2005/6 and we would like to stress we have since taken a number of steps to ensure current recording is more robust and reliable.

"Improvements to record keeping and management of response times have also been made in Avon and Gloucestershire. We can now be confident they accurately reflect performance across the trust area.

"Appropriate controls have now been put in place to ensure the accuracy of response time data, along with additional management support."