The World Cup football, hailed by manufacturers Adidas for its accuracy and criticised by detractors for its tendency to "veer off path", is at the centre of a debate about research ethics, writes Phil Baty.
The ball, to be used in Sunday's World Cup final in Berlin, has been the subject of research at Loughborough University. It might have been hoped that the results would settle, once and for all, arguments about the ball.
But sadly not. The university has refused to answer a single question on this study - including queries about its conclusions, publication plans and sponsorship arrangements - as it is all "confidential".
A Freedom of Information request by The Times Higher found that a study, "Player perception testing of 2006 World Cup ball", led by Loughborough's Roy Jones, head of the sports technology research group, was given ethical clearance in February 2005.
Documents reveal that the university's ethical advisory committee raised concerns and demanded clarification of the application's "sponsorship arrangements".
The researchers had stated that the project was not sponsored but that it was "covered by the sponsor's insurance". The ethics committee noted that "one of the investigators was undertaking the research for Adidas".
When The Times Higher asked Professor Jones to clarify sponsorship arrangements and a publication date, he said: "We have been involved with Adidas in the development of the World Cup ball, but the information is confidential."
Asked if the contract with Adidas meant that he was unable to answer the questions, including those relating to assurances given to the ethics committee, Professor Jones said simply, "yes".
Gill Evans, a Cambridge University professor, who campaigns on issues of academic freedom, said universities had a duty to ensure research integrity in contracts with commercial funders. "It should also ensure that no conflict of interest exists that can potentially undermine the perceived independence of the results," she said.