Japan's Fujifilm has begun clinical trials to test the effectiveness of its anti-flu drug Avigan in treating patients with the new coronavirus, after reports of promising results in China.

Trials in China have suggested Avigan could play a role in shortening the recovery time for patients infected with coronavirus.

"The trial will be conducted on 100 patients until the end of June," a company spokesman told AFP on Wednesday. "We will collect data, analyse them and file for approval after that," he added.

The drug will be administered for a maximum of 14 days to coronavirus patients between 20 and 74 years old with mild pneumonia, the spokesman said. The study excludes pregnant women due to side effects shown in animal testing, he added.

The phase three trial comes after Prime Minister Shinzo Abe said Saturday that the government "will begin the necessary process to formally approve (Avigan) as a treatment against the new coronavirus."

China has already completed clinical trials on favipiravir, the main ingredient in Avigan, the country's ministry of science and technology said last month. Two trials in the country found the drug shortened recovery time for patients, but Fujifilm was not involved in those programmes.

Avigan is currently approved for manufacture and sale in Japan as an antiviral drug for flu. "It is expected that Avigan may potentially have an antiviral effect on the new coronavirus" given the way it works on the flu virus, Fujifilm said in a statement announcing the trial.

Researchers and companies around the world are racing to find a cure for the new coronavirus, with the focus on existing medicines such as anti-malaria and anti-HIV drugs.

Hydroxychloroquine and chloroquine to treat malaria have shown early promise against the COVID-19 illness in early studies in France and China.

But experts urge caution until bigger trials demonstrate their effectiveness. Medical researchers around the world are also working to find a vaccine for the virus, which has so far killed more than 42,000 people globally.