Most crew members aboard a cargo ship off Queensland have been exposed to coronavirus but only one case is current, authorities say.
Queensland Health staff will treat that current case onboard the United Grace, which is anchored off the Sunshine Coast.
All 21 crew members have been tested and seven historical cases of the virus were detected, Chief Health Officer Jeannette Young said on Tuesday.
"Seven have come back as having fully recovered, they are no longer infectious but they've certainly had the infection. Plus then there's that additional confirmed case," she said.
"We'll be caring for that one case onboard ... because they are well."
She said it appeared "most people on that ship have already been exposed to the virus".
The United Grace arrived from Japan last week and had been scheduled to load coal at Hay Point terminal south of Mackay but that did not happen due to coronavirus concerns.
Meanwhile, health authorities will also assess the crew of another vessel of concern, a gas tanker named the Inge Kosan.
That ship, which sailed from Vanuatu, was due to arrive off the southeast Queensland coast on Tuesday.
Dr Young said 11 crew were aboard the Inge Kosan and health staff would go aboard to assess the situation once it was safe to do so.
"We've had, over the last 12 or so months, a lot of experience dealing with ships with positive cases onboard," she said.