At least 41 coronavirus cases have been recorded in an overcrowded military prison outside DR Congo's capital Kinshasa, health authorities said Friday.

Health Minister Eteni Longondo told TopCongo radio that prisoners at the Ndolo jail were still being tested but he expected the number of cases to rise.

Longondo said the current hypothesis was that "a woman who came to leave food" at the jail had transmitted the virus.

Human Rights Watch warned last month that poor conditions in overcrowded DR Congo jails such as Kinshasa's Makala prison -- filled to more than four times capacity -- were a likely virus breeding ground.

The government said on April 8 that at least 1,200 prisoners had been released in order to help stop the virus spread.

To date the vast central African country, one of the world's poorest, has reported 572 confirmed cases -- almost all in Kinshasa -- and 31 deaths.

Authorities confirmed 72 new cases on Thursday, all in the capital except one at Kasindi on the Ugandan border, the largest daily rise since the country's first on March 10.