The corpse of a 17-year-old boy, who died last week, has tested positive for Ebola in Liberia, the country's deputy health minister said late Monday. The news comes seven weeks after the World Health Organization (WHO) declared Liberia Ebola-free after it completed 42 days without a case of the disease.

The teenager died in Nedowein, a town close to Liberia's international airport, about 30 miles south of the capital Monrovia, Tolbert Nyenswah, head of the country's Ebola response, told the Associated Press (AP), adding that he was given a safe burial the next day.

Authorities reportedly tested specimens taken from the corpse before burial following which it was revealed that the teenager had Ebola.

"The only complication is that the person died before we tested the body as part of our surveillance system of testing living and dead people," Nyenswah reportedly said, adding that the teams have begun contact tracing in the Nedowein area. The Ebola Incident Management System team is scheduled to meet Tuesday to look into the incident, he said.

"There is no need for pandemonium; people should go about their normal business," he reportedly said, adding that the Ebola testing of the man's corpse was "a success story for our surveillance system."

Earlier, the last reported case of Ebola in Liberia was a woman in the greater Monrovia area who became sick on March 20 and died one week later, according to WHO.

Nyenswah also reportedly said that no other cases have been reported so far in the country, which was hit the hardest by last year’s outbreak in West Africa. The deadly virus has killed more than 4,000 people in Liberia and more than 11,000 people across West Africa in the past year.

"We have said over and over again there was possibility that there could be a resurgence of the virus in Liberia," Nyenswah said, according to the AP. "But our surveillance teams, our capacity is very strong."

Nyenswah reportedly said that it was unclear how the teenager contracted Ebola. Authorities are reportedly investigating whether the case was linked to travel, although the town where he lived is far from the borders with Sierra Leone and Guinea, where Ebola cases continue to be reported.

With more than 1,300-mile border with Sierra Leone and Guinea, Liberia must remain vigilant, WHO had said in a statement, while declaring Liberia Ebola-free on May 9.