Ivory Coast's firebrand former youth minister and ally of former President Laurent Gbagbo, Charles Ble Goude, has been arrested in Ghana, officials say.
Mr Ble Goude denies leading pro-Gbagbo militias who attacked foreigners and northerners during the unrest which followed disputed elections in 2010.
He has been in hiding since April 2011, when Mr Gbagbo was arrested.
The former president is now awaiting trial at The Hague on charges of crimes against humanity.
Some 3,000 people lost their lives in the four-month crisis after Mr Gbagbo refused to accept defeat.
Several Gbagbo allies have gone into exile in Ghana and they first reported that Mr Ble Goude had been arrested.
"I can confirm that we have arrested someone we believe is the former Ivorian youth minister," Larry Gbevlo-Lartey, Ghana's national security co-ordinator, told the Reuters news agency.
"There's a warrant for his arrest and we have been looking for him for some time now. We're taking him through the process and we'll later hand him over," he said.
Last year, he told the BBC that, as head of the Young Patriots group, he had only organised rallies and meetings and never run a militia.
"I am not chief of militia - I've never bought weapons, we went to the streets against those who had weapons, we were bare-handed," he said.
He said he was ready to go the International Criminal Court in The Hague to clear his name if that is what it took.
Mr Ble Goude was first put under UN sanctions in 2006 accused of inciting attacks against UN personnel.
During the unrest, people from northern Ivory Coast were seen as supporters of Mr Gbagbo's rival, President Alassane Ouattara.