Shelley Rudman won a silver medal in the 2006 Turin Winter Olympics

The Public Accounts Committee's report said performance had been "overstated" against the target for medals won at major international championships.

It also said performance information should only report "accurate figures".

The report, released on Tuesday, said UK Sport had included 83 medals won in events not taken into account in setting future Olympic targets.

The report also called for clearer goals, better assessment of progress and more accurate performance reporting.

"While Great Britain's position in the Athens Olympic and Paralympic medal tables was broadly on target, many funded sports did not meet their individual medal targets and 10 sports won no medals at all," it said.

The conclusions show that the government was not completely transparent over the medal target for 2012 and that it fiddled the figures in previous games by including extra sports Shadow sports minister Hugh Robertson

"To the extent that value for money can be measured in terms of medal success, UK Sport should look to achieve a better return from its expenditure in future."

The committee's report also urges organisations representing the different sports to set performance targets for the London Games in 2012 and calls on UK Sport to monitor the athletes it supports more closely.

UK Sport is a public body which allocates funding to governing bodies of sport and individual athletes.

The Public Accounts Committee (PAC) report examined the use of lottery money by UK Sport to support elite athletes competing in Athens in 2004 and Turin 2006 and the plans for the Olympics in Beijing in 2008 and London in 2012.

The PAC also reported that UK Sport's funding submission for 2012 referred to a goal of finishing fourth in the 2012 Olympics, although the published funding agreement between the Department for Culture, Media and Sport (DCMS) and UK Sport said the goal was finishing fifth.

'Damning indictment'

"Yet, when recalled by the committee, the department and UK Sport maintained there was no target and attributed the confusion to their inappropriate use of the term 'target'," the committee said.

The government has announced it will have a �600m package in the run-up to the 2012 Olympics.

This includes �300m from the National Lottery, �200m from government and �100m to be raised from commercial sponsorship.

The Conservatives demanded an urgent statement from the government following the report, with the shadow sports minister Hugh Robertson calling it "a damning indictment" of the way the DCMS had conducted its business.

We recognise the need for clear transparency and accountability in our own actions and with the sports and athletes we fund UK Sport chief executive John Steele

"The conclusions show that the government was not completely transparent over the medal target for 2012 and that it fiddled the figures in previous games by including extra sports," he said.

"This smacks of dishonesty, which is entirely unacceptable from both the government and a public body like UK Sport.

"These are extremely serious conclusions and the secretary of state needs not just to brush these away but to make an urgent statement to the House."

A DCMS spokeswoman said: "We welcome the PAC report and recognise that a majority of these recommendations are already being implemented by UK Sport."

John Steele, chief executive of UK Sport, said: "As the lead agency for elite sport in the lead-up to 2012, we recognise the need for clear transparency and accountability in our own actions and with the sports and athletes we fund.

"We therefore welcome the majority of the recommendations made by the PAC and have already acted on them in relation to our own reporting and assessment of progress by the governing bodies."