Defra and other agencies have published reports into the outbreak earlier this year of avian influenza at the Bernard Matthews turkey farm/factory in Holton, Suffolk.
There is a Defra press release, detailing what has been published, namely a Defra epidemiological report, and a joint final report by the Food Standards Agency and others.
There is another Defra press release about their epidemiological report, which links to the epidemiological report itself.
There is an FSA press release about their investigation. I cannot immediately find this final FSA and other agencies report.