(IDEX Online) - Canada's oldest diamond mine has been closed to prevent further spread of coronavirus.Some employees claim they've been told it could be four months before the Ekati mine re-opens, according to local media reports. Ekati has been in operation at a remote location 300km north east of Yellowknife in Northwest Territories, close to the Arctic Circle, since 1998.Calgary-based owners Dominion Diamond Mines, which has 1,800 employees, said none had tested positive for Covid-19.But it said in a statement: "This preventative action was determined to be a necessary step given the rapid spread of the virus, the remote location of the Ekati mine's operations and the high frequency of air travel required for employees and support staff to access mining operations."