Some of those arrested were tortured in prison in the town of Bouafle and forced to pay 100,000 CFA francs ($200) to secure their freedom.

"Ill treatment and torture resulted in the death of 12 people in the prison on Feb. 22 and another at a hospital on Feb. 27," the world body said in a statement.

"The forest guards of Marahoue National Park inflicted the acts on them," it said.

The world's top cocoa grower is already under scrutiny for its human rights record.

A UN report late last year catalogued massacres, torture and widespread use of rape, child soldiers and death squads in both government-held and rebel-controlled areas during more than two years of civil war.

The investigating commission which compiled the report called for the UN Security Council to ask the International Criminal Court to prosecute those guilty of the worst crimes.

A representative of an Ivorian human rights group also investigating events at Marahoue park said the villagers did not want to leave because they farmed land there. He said guards at the prison in Bouafle had also tortured the detainees.

"Most of the villagers who were arrested were beaten and some were shot in the leg when they tried to escape the forest," the representative of the Ivorian Movement for Human Rights said.

"Some villagers had their houses and their crops burned."