The COVID-19 outbreak at Cedar Meats in Melbourne's west is being investigated by WorkSafe.
A spokesman for WorkSafe has confirmed it will be investigating the Brooklyn abattoir, which is linked to 88 infections.
The probe will examine whether social distancing measures were in place at the abattoir and if workers were provided with appropriate personal protective equipment and hand sanitiser.
The state government and Cedar Meats' management have defended their handling of the outbreak, including the decision to allow staff to work for several days after workers tested positive.
Cedar Meats general manager Tony Kairouz says he has been advised by WorkSafe of its investigation.

88 cases have been linked to the Cedar Meats facility in Victoria. Source: AAP
"We welcome it. We will co-operate fully," Mr Kairouz said in a statement to AAP on Wednesday.
It comes as another cluster continues to grow in the city's north.
Three more infections have been linked to McDonald's Fawkner, bringing the total number of cases linked to the fast-food restaurant to six.
That number could rise as test results for 92 workers continue to come back.
The restaurant has reopened following a deep clean and is being staffed by workers from surrounding outlets, a McDonald's spokesperson said.
Meanwhile, a worker at a poultry processor has also tested positive to the virus.

There are six confirmed cases of coronavirus linked to McDonald’s in Fawkner. Source: SBS
Health authorities did not name the facility but said it was an isolated case. The business is not an abattoir and contact tracing is under way.
Victoria's coronavirus count stands at 1514, with seven new cases confirmed on Wednesday.
People in Australia must stay at least 1.5 metres away from others. Check your state’s restrictions on gathering limits. Testing for coronavirus is now widely available across Australia.
If you are experiencing cold or flu symptoms, arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080.
The federal government's coronavirus tracing app COVIDSafe is available for download from your phone's app store.
SBS is committed to informing Australia’s diverse communities about the latest COVID-19 developments.