"Two cases which tested positive for Ebola were confirmed overnight in South Kivu, in Lwindi district in the Mwenga region," it said in a statement.
"A 26-year-old victim died and (one of their) children who tested positive is still alive and being treated," it said.
More than 1,900 people have died from Ebola in the Democratic Republic of Congo since August 1, 2018, when the hemorrhagic virus erupted in North Kivu province and spread to neighbouring Ituri province.
South Kivu Governor Theo Ngwabidje told reporters: "Teams from the national anti-Ebola coordination campaign arrived yesterday to provide support."
The Ebola virus causes fever, vomiting and severe diarrhoea, often followed by kidney and liver failure, internal and external bleeding.
The disease is spread by contact with infected bodily fluids and is fought with time-honoured but laborious techniques of tracing contacts and quarantining them.
The outbreak is the 10th since Ebola was identified in 1976.
It is the deadliest on record after more than 11,000 people was killed in Guinea, Sierra Leone and Liberia between 2014-2016.
'Two cases which tested positive for Ebola were confirmed overnight in South Kivu, in Lwindi district in the Mwenga region,' it said in a statement.