A Chinese mining company in Papua New Guinea claims to have immunised its employees against Covid-19 in an apparent trial as Australia and China prepare for a new “vaccine diplomacy” battle for influence across the region.

This week Australian Prime Minister Scott Morrison vowed to help the nation’s “Pacific family” and key Southeast Asian partners gain access to a successful coronavirus vaccine, when one was found, through a foreign aid programme.

The Australian newspaper has learned China may have begun trialling a coronavirus vaccine in the region on employees of its state-owned enterprises.

The PNG government said the Health Department was investigating the claim by Chinese-owned Ramu Nickel that its employees had been vaccinated.

A statement from the company declared 48 employees had been vaccinated with “SARS-COV-2 vaccine” on August 10.

The statement warned that any Covid testing of its employees within a week of the claimed vaccination “may show positive results” due to antibodies produced in the recipient’s body.

The Chinese government has given the green light for two potential vaccines to be trialled by state-owned firms with employees overseas, and another to be trialled by the nation’s military.