Human rights groups are urging Equatorial Guinea officials to investigate what they call the possible "enforced disappearance" of a top human rights lawyer.
Fabian Nsue Nguema went missing on Monday after he entered the notorious Black Beach prison in the capital, Malabo, to visit a client.
A rights group focused on Equatorial Guinea, EG Justice, says multiple sources report the lawyer has been detained by government security forces and that his car remains parked outside the prison.
However, the group says the government has neither confirmed nor denied it is holding him.
In a VOA interview, EG Justice program director Joseph Kraus said Equatorial Guinea has a long history of human rights violations, including forced disappearances and kidnappings.
"In 2010, for example, there were four individuals who were living outside the country as refugees in Benin," said Kraus. "They were covertly kidnapped, brought back into the country, held without any access to their families or to lawyers for several months and they were subjected to a sham military trial and convicted. Within one hour of their conviction, they were executed without even being allowed to see their families."
Human rights groups have long considered Equatorial Guinea one of Africa's most repressive governments. Activists say President Teodoro Obiang Nguema rules the country with an iron fist while enriching himself and his associates.
EG Justice says Nsue has served as legal counsel for members of the opposition, and has been the target of government harassment in the past.
In a statement, Human Rights Watch calls Nsue's disappearance a "grave concern" and urges the government to immediately clarify his whereabouts.