The ethnically Kazakh couple died on May 1 after ingesting raw marmot kidney - traditionally believed to have health benefits, according to Ulaanbaatar's World Health Organization spokesperson Ariuntuya Ochirpurev.
Immediately a six-day quarantine was imposed, stranding numerous tourists.
The town of Tsagaannuur, near the border between Mongolia and Russian Federation, was quarantined for six days last week after the man and woman were diagnosed posthumously with plague, a World Health Organization (WHO) official told the Washington Post.
The couple died of "multiple organ failure", the outlet reported. These included tourists from South Korea, Kazakhstan, Sweden, and Switzerland who were given antibiotics as a preventative.
The couple was diagnosed posthumously with plague, the age-old disease caused by the bacterium Yersinia pestis.
Humans can catch the plague through flea bites or, as in this case, through contact with the tissue or bodily fluids of an infected animal, according to the Centers for Disease Control and Prevention.
The fleas that are on animals can be the transmitters of the plague to the humans and if they do not seek professional help and they do not treat the disease, according to the BBC, the fatality rate is of 30% to 60%. However, if an individual does not receive care immediately, they can become seriously ill or die. Native governor Aspirin Gilimkhaan advised AFP that no different instances have been reported within the space because the quarantine was lifted Monday.
Symptoms of the bubonic plague are swelling of the lymph nodes, weakness, chills, headache, and fever.
The Black Death wiped out millions of people in the Middle Ages but cases are now very rare.