A senior expert on hospital decontamination methods has told Panorama how he was asked to destroy all evidence of a government-commissioned report into standards of decontamination in English hospitals.
He had originally been told that Alan Milburn, the Secretary of State for Health, wanted his team to proceed with the report with the utmost urgency.
Scientists now say that there is a real risk of spreading vCJD, the human form of mad cow disease, via surgical instruments used in operations.
Only if these instruments are cleaned to the highest standards is the risk of spreading vCJD minimised.
Infection
New research revealed for the first time on Panorama, shows that contact with animal brain tissues infected with scrapie - a disease very closely related to vCJD - for as little as five minutes can render a steel wire highly infectious.
The research, conducted by a team led by Professor John Collinge at Imperial College, London, shows that this infectious wire can infect another animal brain after contact with it for as little as 30 minutes.
The decontamination report is known in government circles as "the survey that didn't take place". It investigated how well surgical instruments were being cleaned inside the NHS.
It was commissioned by the Department of Health amid fears that contaminated surgical instruments might contribute to the spread of vCJD.
Serious flaws were revealed in hospitals' surgical equipment cleaning procedures. NHS Estates, an executive agency of the Department of Health, told microbiologist David Hurrell to destroy all copies of the report.
Mr Hurrell said: "It asked me to destroy or return all the copies of the reports and draft reports and data that I had got and to delete all electronic files."
Mr Hurrell received a letter dated 26 September, 2000, from the then chief executive of NHS Estates Kate Priestley.
Confidential
It read: "In light of the somewhat negative outcome... there is a need to ensure, at the express request of ministers, that the final version and earlier draft reports remain strictly confidential."
The letter went on to say that the benefits of the study "may be compromised if the findings of the report were to enter the public domain in an inappropriate or unauthorised fashion".
Mr Hurrell was part of a team of experts who visited 43 NHS hospitals to assess the standards of decontamination of surgical equipment. His job was to co-ordinate all the technical data for the report.
Mr Hurrell told Panorama that the number of hospitals visited was based on advice from the department's own statisticians, to provide the report with statistically significant data.
He went on to say that the project was first discussed in August 1999 at the Department of Health.
Analysis of the findings from the first six or seven hospitals prompted him to alert the Department of Health immediately.
He said general hospital decontamination cleaning procedures were 'barely adequate' in the majority of hospitals.
The report was being readied for printing in July 2000. But on 26 September, 2000, Mr Hurrell received the letter from NHS Estates' chief executive telling him to destroy all copies of the report.
The Department of Health refused a request from Panorama to interview the ministers concerned. In a written statement, they said "the report was not prepared for publication".