Auditors have blamed Britain's Institute of Animal Health (IAH) for poor labelling and record-keeping practices that allegedly led to years of BSE research being wasted.

The Department of Environment, Food and Rural Affairs commissioned two audits last month, after tests by the Laboratory of the Government Chemist revealed that samples from brains being studied for signs of BSE in sheep had actually come from cattle (see Nature 413, 760; 2001). This triggered a controversy over whether IAH researchers had spent five years accidentally testing the wrong brains.

But the institute's director, Chris Bostock, rejects the auditors' reports and denies that a mix-up occurred at the IAH.

An audit by the UK Accreditation Service (UKAS), based in Newbury, Berkshire, was made public on 30 November. It found that the IAH's record-keeping system fell short of accepted good practice, that “there was no formal documented quality system” and that this “was inadequate to give confidence in the chain of custody of the samples”.

The London-based auditors Risk Solutions said that poor labelling could have allowed a mix up of the original 1990 sheep tissue samples with bovine samples that had been stored in the same freezer.

In a strong rebuttal, the institute said that it had in place “comprehensive and documented formal procedures” that met government standards.

Bostock says the audits were carried out hastily, and failed to inspect the institute's overall record-keeping system. “The audits fail to convince me that a mix-up occurred,” says Bostock. The IAH is now completing an internal audit of the affair.

“It's time to move on,” he says, adding that researchers should concentrate on the critical question of whether BSE is already in sheep flocks (see pages 576–577).