According to records released yesterday by congressional investigators, tests were conducted in 2008 by a major egg producer after it was indicated that there was presence of the dangerous bacteria in its henhouses.

A salmonella outbreak that has sickened more than 1,500 people has been linked to the producer.

Sponges swabbed on egg conveyor belts and other areas in Wright County Egg’s barns showed the presence of salmonella bacteria, including the strain that infects eggs and causes human illness were shown by 73 instances over about two years as per the records.

Salmonella enteritidis’s presence was seen in at least one case by further tests.

The records the company provided to Congress states that it was not clear if any steps to protect public health were taken by Wright County Egg after receiving the positive test results.

A hearing on Tuesday has been kept by Representative Bart Stupak, Democrat of Michigan and chairman of the House Subcommittee on Oversight and Investigations at which DeCoster is expected to testify.

DeCoster has been asked by Stupak and Representative Henry A. Waxman, Democrat of California and chairman of the Energy and Commerce Committee, to be prepared to explain what actions were taken in response to the positive test results.