PORT HAWKESBURY, N.S. -- An oil tanker has been anchored off Cape Breton since Sunday because of concerns several crew members may have contracted COVID-19.

Karl Risser, Atlantic inspector for the International Transport Workers Federation, said Thursday one crew member on the STI San Telmo had tested positive and is in quarantine in a Sydney, N.S., hotel.

Risser said he's been told another seven members of the crew have also tested positive for COVID-19.

"From what I understand, the situation is being monitored (by health officials) and everybody is stable," he said.

Risser said the vessel had been sailing to Montreal from Antwerp, Belgium, and his union, which represents foreign seafarers, will "keep and eye on things" until the ship gets permission to move.

There's no word on how many crew members are on board, but Risser said an oil tanker of its size typically has a crew of up to 22. "They work in confined spaces, so (the virus) can travel quite fast," he said.

On Wednesday, Transport Canada spokeswoman Cybelle Morin said in an email that the federal department was aware "of potential cases of COVID-19" involving a foreign-flagged vessel.

Morin said the vessel presents no risks to port personnel or marine safety and can leave its anchorage only when the Public Health Agency of Canada agrees. "Crew members on this vessel are taking precautions as required," she said.

In an email Thursday, the Public Health Agency of Canada confirmed it was notified about an ill crew member aboard the vessel last Friday.

The agency said the individual was subsequently taken to hospital where they tested positive for COVID-19. It said the remaining crew were isolating on board the ship, adding that agency quarantine officers were monitoring the situation closely and receiving daily updates about the crew's health status.

The vessel's local Canadian agent, SMK Tanker Agency in Longueuil, Que., did not provide comment when contacted Thursday.

This report by The Canadian Press was first published April 15, 2021.