An Alliance Group spokesman yesterday confirmed the company was working through an "employment matter".
"The health and wellbeing of our people is paramount and the co-operative put in place significant measures over the lockdown to prevent the spread of Covid-19 and keep our employees safe.
"We are currently working through an internal employment matter involving an alleged breach of Covid-19 restrictions during the lockdown.
"This is an ongoing process and it would be inappropriate to comment further at this time."
The plant is also under investigation after a worker at the plant injured their hand on the job on Tuesday.
The spokesman confirmed an employee had been injured following an incident at the plant.
"He received treatment at Southland Hospital and is now recovering.
"Alliance is supporting the employee and speaking with WorkSafe New Zealand.
"We have launched our own internal inquiry. It would be inappropriate to comment further at this stage.”
A WorkSafe New Zealand spokeswoman said staff were now making inquiries.
