Investigators from the World Health Organization (WHO) looking into the origins of coronavirus in China have discovered signs the outbreak was much wider in Wuhan in December 2019 than previously thought, and are urgently seeking access to hundreds of thousands of blood samples from the city that China has not so far let them examine.

Axar.az reports citing foreign media that the lead investigator for the WHO mission, Peter Ben Embarek, told CNN in a wide-ranging interview that the mission had found several signs of the more wide-ranging 2019 spread, including establishing for the first time there were over a dozen strains of the virus in Wuhan already in December. The team also had a chance to speak to the first patient Chinese officials said had been infected, an office worker in his 40s, with no travel history of note, reported infected on December 8.

Ben Embarek, who has just returned to Switzerland from Wuhan, told CNN: "The virus was circulating widely in Wuhan in December, which is a new finding."