Former head of the Food Standards Agency (FSA) and current technical director at Tesco Tim Smith lobbied the Government about plans to publish food poisoning contamination rates for supermarket chicken, a newspaper has reported.
The Guardian said it understood that Mr Smith warned the Department of Health this summer that revealing the results could provoke a food scare and damage the industry.
Mr Smith's appointment at Tesco in October 2012 had to be approved by David Cameron on advice from the Advisory Committee on Business Appointments, with the proviso that he did not lobby on behalf of the supermarket for two years.
The FSA is set to publish its second quarterly round of results of its year-long survey into the prevalence and levels of campylobacter on shop-bought fresh whole chilled chickens and their packaging.
The results, due to be released tomorrow, will include a breakdown naming major retailers for the first time.
A survey carried out by the FSA previously found that almost three-fifths of shop-bought chickens tested positive for campylobacter.
The bug was present in 59% of birds tested, and in 4% of samples it was identified on the outside of the packaging.
The FSA attracted criticism for deciding against naming individual retailers in the first set of results in the summer, saying: "As soon as we have enough data to robustly compare campylobacter levels in different retailers, we will share that data with consumers."
The Guardian said shadow food and farming minister Huw Irranca-Davies wrote to Health Secretary Jeremy Hunt earlier this month asking for "unequivocal assurance" that Mr Smith did not lobby his department inappropriately over campylobacter and in breach of his conditions of employment, but he has not received a reply.
The newspaper said it had been told that Mr Smith met a senior civil servant in the Department of Health's public health division, raising concerns about publishing the test results.
The newspaper said it had put in freedom of information requests to the department last month asking which companies lobbied over campylobacter and what had passed between the departments.
But it said the department refused to give any information and that decision was now being appealed against.
A Tesco spokeswoman said: "Tesco is committed to the reduction of the industry-wide issue of campylobacter in poultry.
"We work in close collaboration with our suppliers, other retailers and relevant food and health authorities to address the issue at all stages of the supply chain."