More than a quarter of the confirmed novel coronavirus cases in Brazil's southernmost state of Rio Grande do Sul are among meat plant workers, the labour prosecutors' office said.

The prosecutors said in a statement that an estimated 2,399 employees from 24 slaughterhouses in 18 municipalities of the state have been infected. That equates to 25.7 per cent of the 9,332 confirmed cases of coronavirus in Rio Grande do Sul as of Sunday, according to health ministry statistics.

The findings corroborate evidence that meatpackers have become hotspots in Brazil for Covid-19. Overall, Brazil has more than 500,000 cases and nearly 30,000 deaths, according to a Reuters tally.