Allieu Kondewa was a leader of the pro-government Civil Defence Forces (CDF), a notorious paramilitary unit that recruited traditional hunters to fight rebels during the country's brutal 1991-2002 civil war.

He was convicted in 2007 to a 20-year sentence on charges of war crimes and crimes against humanity, including murder, issuing collective punishment and recruiting child soldiers.

He spent nearly 10 years in prison in Rwanda under a special agreement as war-ravaged Sierra Leone did not have proper detention facilities.

The Residual Special Court for Sierra Leone, based in Freetown, said Monday that Kondewa was the second person convicted by the court to be released, after the CDF's "War Commander" Moinina Fofana was released in 2018 after completing a 15-year sentence.

Kondewa had been imprisoned in Rwanda until 2018, since Sierra Leone did not have sufficient detention facilities to hold him.

That year the court granted a conditional early release for him to serve the remainder of his sentence in his community in the southern Sierra Leone city of Bo, under strict oversight.

The Sierra Leone civil war, financed largely by so-called blood diamonds, left 120,000 people dead and tens of thousands mutilated.

As a parallel force to the regular army, the CDF fought rebels of the Revolutionary United Front (RUF) and the Armed Forces Revolutionary Council.

The CDF was alleged to have "eliminated" civilians suspected of collaborating with rebels, either through shooting them, hacking them to death or burning them alive.

Several other people remain in prison after being sentenced to longer prison terms by the special court, including Charles Taylor, the former Liberian warlord convicted of fuelling the conflict in Sierra Leone.

Taylor is currently serving a 50-year sentence in a British prison after being convicted in 2012 by a special court in The Hague over war crimes in Sierra Leone -- the first ex-head of state to be jailed by an international court since the Nazi trials at Nuremberg in Germany after World War II.