More than seven weeks after Liberia was declared free of Ebola, a young man was found dead of the disease on Sunday, leading some to worry if this could be the start of a new outbreak, says the country's deputy health minister.

Liberian officials on Tuesday have quarantined a neighborhood near the capital city of Monrovia where the body was found; The Wall Street Journal reports.

Deputy Health Minister Tolbert Nyenswah said dozens of people were under observation after potentially coming into contact with the boy who died on Sunday. His body tested positive for the Ebola virus this week.

Authorities are currently trying to determine how many people the 17-year-old boy had contact with during the week when he was potentially infectious with Ebola. His immediate family is already under quarantine.

It's unclear how the teenager contracted the disease, considering the World Health Organization declared Liberia free of Ebola on May 9 -- 42 days (two incubation periods) without a newly recorded infection; according to the Centers for Disease Control and Prevention.

Investigators said it's not known whether the teen had traveled to Guinea or Sierra Leone, where there are still cases of the disease, or if he somehow contracted the virus within his own community.

The health ministry expects to have a list of the young man's contacts by the end of the day Tuesday.

Previously the country had lost nearly 5,000 people to a year-long epidemic that claimed more than 400 lives a week at its peak in September.

Now the new infection could be a major setback to the Liberia's President Ellen Johnson Sirleaf, who is struggling to make up for what the World Bank says could be a $240 million blow to her country's poor economy from the epidemic.