Chinese scientists' research on tracing the origins of the coronavirus were carried out based on suggestions provided by the World Health Organization, Shen Hongbing, director of the Chinese Center For Disease Control and Prevention, told a news conference on Saturday.

He recalled that WHO and Chinese experts jointly traced the virus origins from January to February of 2021, visiting the seafood market in Wuhan, Hubei province, where the first COVID-19 cases were reported in China, and providing suggestions for the next step.

"Therefore, a series of followup research made by CDC scientists were conducted in accordance with the suggestions from the WHO's tracing report," he added.

The followup analysis results showed that DNA data in the environmental samples from the market could not provide any new clues to the origin of the virus, he said, adding that CDC experts summarized the findings into a scientific paper in February 2022.

The experts submitted the paper to the Nature for review and made them public through a preprint platform, and also uploaded the original data to GISAID in line with the international practice, according to him.

Now, relevant data have been disclosed in four databases at home and abroad, and the paper has also been formally published in Nature, he added.

When asked why it took over three years for China to make public the virus data collected in Wuhan in January 2020 instead of sharing it immediately, he said: "Based on the WHO's recommendations, Chinese scientists conducted further analysis, and the submission required a process."

"The preprint had been published and the subsequent data had also been publicly released, so we didn't delay the release of the data, nor delayed them intentionally," he added.