A Timaru-based employee at a meat processing company has tested positive for Covid-19.

Alliance Smithfield confirmed a night shift worker, a man aged in his 40s, had tested positive and that the plant was continuing to operate.

General Manager People & Safety at Alliance Group, Chris Selbie, said the employee had completed a night shift at the company's Smithfield plant in Timaru on April 6 before notifying his manager the following day that he felt unwell and went into self-isolation.

"He received notification of a positive test on Tuesday but has not been back at the plant since April 6.

"The employee is now in isolation and recovering well at home. Alliance Group has spoken with the District Health Board and public health officials are now tracing others who have been in close contact with the individual," Selbie said.

On Wednesday, staff were sent a memorandum confirming a colleague had been diagnosed with coronavirus.

"Our thoughts are with the employee and his family. The employee did the right thing and alerted his manager. We're now supporting him and his family.

"We are working hard to make sure we keep people safe, manage any animal welfare issues with farmers, preserve jobs and look after our local communities."

Although 12 other people have been diagnosed with the virus, this was the first confirmation of the disease at a specific location in South Canterbury.

The Smithfield plant remains operational, based on advice from the South Canterbury District Health Board, Selbie said.

He said from the outset the company had implemented the Meat Industry Association Industry standard that has been agreed with the Ministry for Primary Industries.

"Our people are working two metres apart unless other effective Personal Protective Equipment and measures are in place to protect them such as safety glasses, gloves, splash guards, face-masks or visors.

"We have further increased the cleaning/disinfection of processing areas. Our people are also being regularly reminded about the importance of good hygiene practice at work and at home. We are staggering breaks to avoid large numbers of people in the same place and implementing restrictions on transport to/from work."