Haitian former Prime Minister Yvon Neptune has been released from prison after serving more than two years without being convicted of any crimes.
Mr Neptune's health is said to have deteriorated dramatically in jail
He had been held on charges relating to the killing of opponents of ex-President Jean-Bertrand Aristide shortly before he was ousted in 2004.
Mr Neptune has always denied the allegations and held repeated hunger strikes while in jail.
He was taken by ambulance to a UN-run hospital for treatment on his release.
The UN mission in Haiti (Minustah) issued a statement saying the health of the 59-year-old politician had declined dramatically in prison.
A lawyer for Mr Neptune - who served as prime minister from 2002 to 2004 - said his client had been released for humanitarian reasons.
"After the hospital, he is free to go home. I'm confident that charges will be dropped," Mario Joseph said.
The interim administration installed after Mr Aristide's fall from power, and the recently-elected government, had faced strong international pressure to free Mr Neptune, whose imprisonment became a rallying call for Aristide supporters.
President Rene Preval, who was elected earlier this year, is himself a former ally of Mr Aristide.
Mr Aristide was forced from office in an armed rebellion in February 2004 and is currently living in exile.
Thousands of UN peacekeepers were later deployed to try to quell the unrest which continues to plague the Caribbean nation.