ABOUT two dozen cases of COVID-19 have been recorded among the crew of an Australian warship on its way to deliver humanitarian aid to virus-free Tonga, authorities said on Tuesday.

Authorities in Tonga, hit by a massive volcanic eruption and a tsunami on Jan. 15, have asked for aid to be delivered without human contact amid concerns a COVID outbreak would be devastating for the tiny Pacific island nation.

The HMAS Adelaide which left from Brisbane carrying large quantities of supplies, helicopters, water purification equipment, additional humanitarian aid, and also an Australian Army engineer contingent, is due to arrive in Tonga in a few days.

Australia's Defence Minister Peter Dutton said 23 personnel have tested positive to COVID on the vessel.

“We will work with the Tongan authorities to keep that vessel at sea to make sure there is no threat and obviously the Tongan government is discussing that at the moment,“ Dutton said on Sky News.

“Obviously they need the aid desperately but they dont want the risk of COVID,“

Dutton's office told Reuters the HMAS Adelaide was still on its way to Tonga. There are about 600 crew onboard.

Aid flights from Australia and New Zealand arrived in Tonga last week with essential supplies, but the transfer of goods was done in a contactless way. One Australian aid flight was forced to return to base when a COVID-19 case was detected midflight.

A New Zealand aid vessel landed last week and more aid is enroute by air and sea from New Zealand, Japan and Britain.

The United Nations, Red Cross and other relief agencies on the ground in Tonga have warned that a COVID-19 outbreak in the island would be catastrophic at this time.

The Hunga Tonga-Hunga Ha'apai volcano eruption triggered a tsunami that destroyed villages and resorts and knocked out communications for the nation of about 105,000 people. Three people have been reported killed, authorities said. - Reuters