Independent tests at RCL Foods’ processed meat factory have not found any traces of a listeria strain that has killed 180 people since January last year, the South African food producer said on Friday.

#Listeriosis outbreak: What you need to know

Health authorities ordered a recall of processed meat known as “polony”, made by Tiger Brands and RCL Foods, nearly two weeks ago after they identified the source of the listeria outbreak – the world’s worst – that has seen 948 reported cases since January 2017.

The government traced the strain that caused the outbreak to a factory owned by Tiger Brands, sending its shares tumbling, while RCL Foods’ Wolwehoek plant was also put under investigation.

However, RCL said on Friday independent tests showed no traces of the particular strain of bacteria at its plant.

“Tests conducted by an independent laboratory in France, which is considered to be a leading expert in this field, have shown that the plant is clear of the ST6 listeria strain,” the firm said in a statement.

The authorities said they were also examining a second Tiger Brands factory and have not said when they might conclude tests on RCL Foods’ plant.

Both companies, which say they are cooperating with the authorities, have suspended processed output at their plants.

Reporting by Tanisha Heiberg; Editing by Tiisetso Motsoeneng and Mark Potter