The report looked at inpatient waits

In three of the 41 trusts studied the Audit Commission found waiting list figures had been manipulated.

The three were East and North Hertfordshire, South Manchester University Hospitals and Scarborough and North East Yorkshire Healthcare NHS trusts.

Fiddles included offering unsuitable appointments, then putting patients to the bottom of the list if they could not attend and simply excluding people from lists.

The South Manchester trust, which includes Wythenshawe Hospital, is to have its one-star rating removed because of the findings, making it a no-star hospital.

In all three, action has been taken to investigate and deal with the problems. Some staff have been suspended.

In 19 other trusts it was found there had been errors in how figures were reported.

Unacceptable

It is completely unacceptable in a public service to be deliberately fiddling the figures Alan Milburn Read our Q&A guide

Health Secretary Alan Milburn told the BBC: "It is completely unacceptable in a public service to be deliberately fiddling the figures in the way that a small minority of senior NHS managers and NHS trusts have done.

"Where that has happened swift action has been taken. We are not going to have a situation in the NHS where a few bad apples are spoiling the reputation of the overwhelming majority.

"Most organisations have targets, they are part of the currency of modern management, and we should be unapologetic about setting demanding targets on waiting times in particular because waiting is the public's number one concern about the NHS."

The Audit Commission said in the majority of cases, the manipulation of figures was "unlikely" to have affected individual patient's care.

But it said some practices, such as offering appointments at short notice, and putting patients to the back of the queue if they could not attend, would not be considered "reasonable" by patients, even though they fall within government guidelines.

The report comes 18 months after another watchdog, the National Audit Office, first identified waiting list "fiddles".

There has been concern that trust managers feel compelled to meet government pressure to meet targets, leading them to massage their results.

Breast cancer waits

The Audit Commission looked at the trusts' waiting list figures from March 2001 to autumn 2002 at the request of the Department of Health.

It would clearly be rather unbelievable to argue that none of it was due to pressure from above James Strachan, Audit Commission

It looked at inpatient and outpatient waits in five areas of clinical care.

All trusts will be subject to spot checks in a five year rolling programme. Many of the first group were selected because concerns had already been raised over their waiting list figures.

Some of the problems discovered date from after the NAO report was issued and trusts were warned about the need to report accurately.

In 93% of trusts examined, auditors said there were weaknesses in the systems for reporting and measuring waits, increasing the risk of reporting errors.

In one trust IT systems were so poor, the auditors were not able to access the information they needed.

However, three trusts scored particularly well in the audit - Nottingham City Hospital, Royal Devon and Exeter Healthcare and Salisbury Healthcare NHS Trusts.

And the Audit Commission found the two-week waits for patients with suspected breast cancer were well managed.

Targets

Following the report, all trusts will be asked by the Department of Health to look at their systems for monitoring waiting times and ensuring training and IT is adequate.

The department has accepted Audit Commission recommendations that there should be an investigation into why figures were misreported.

James Strachan, chairman of the Audit Commission, told BBC News Online: "It's not true that this is all about pressure, but it would clearly be rather unbelievable to argue that none of it was due to pressure from above."

Dr Gill Morgan, chief executive of the NHS Confederation, which represents trust managers, said: "Any evidence of trusts manipulating waiting list figures is clearly unacceptable.

"However, must not condemn NHS management on the basis of the actions of a small minority of trusts."

Neil Goodwin, chief executive of the Greater Manchester Health Authority that manages the South Manchester Acute Trust, said he did not understand the motives behind the employees' actions, and refused to blame the pressure to meet targets.

He said two of the four people involved had resigned from the NHS while the other two still had jobs.

"It is up to their employers to determine whether or not they are trustworthy in the jobs they now occupy," he told BBC Radio Four's Today programme.

Shadow Health Secretary Dr Liam Fox said the findings were shocking, and blamed the government for distorting priorities.

Liberal Democrat health spokesman Dr Evan Harris said: "No one has any faith in the validity of waiting list figures now."