Ignace Murwanashyaka, the founding head of the Democratic Forces for the Liberation of Rwanda (FDLR), a terrorist group based in Eastern DR Congo, was pronounced dead on Tuesday evening.
Murwanashyaka, according to German media, died from Mannheim University Clinic where he had been rushed from prison last week following a severe illness .
"FDLR president Murwanashyaka was held in isolation in jail as a terrorist leader and was gravely ill recently. Last week he was transferred as a prisoner to Mannheim university clinic where he died on Tuesday. Cause of death (is) yet to be formally established," reads a tweet from Dominic Johnson, a German journalist.
Johnson, the Africa Editor for Taz, a German newspaper, has reported on the Great lakes region, mainly DR Congo for the past several years.
Murwanashyaka, 56, had been in jail since 2009.
On September 28, 2015, he was convicted on five counts by the Higher Regional Court of Stuttgart of aiding and backing war crimes and leading a foreign terrorist organisation.
He was eventually sentenced to 13 years in prison.
However, he appealed the sentence.
And, on 20 December 2018, the German Federal Court partially overturned his conviction, arguing that the ruling on first instance was contradictory in some parts. It sent the case back for retrial.
The cause of his death is yet to be formally established.
In 2001, Murwanashyaka became the head of FDLR, considered to be the main cause of insecurity in the African Great Lakes Region, according to Trial International, an organisation whose mission is to fight for justice whenever crimes of an international nature are committed.
He was accused of coordinating human rights violations by the FDLR between January 2008 and July 2009.
The FDLR has killed several hundred civilians, pillaged and burned down numerous villages and left many women raped or subjected to other forms of sexual violence.
Numerous child soldiers were allegedly recruited by the force in order to carry out such operations.
In 2005, the United States blacklisted the FDLR as a terrorist group, which was followed by UN sanctions against the outfit's leaders, including Murwanashyaka.
The sanctions included a travel ban and freeze of assets owned by Murwanashyaka and other FDLR leaders.
Travelling on Ugandan passport
Despite global sanctions Murwanashyaka faced, in 2005 he was facilitated by immigration officials to acquire a Ugandan passport, on which he would travel to Germany, where he was eventually arrested.
He was in Germany - a country where he had lived for a long time - as part of a fundraising drive for the terror group.
Arrest, legal action
Murwanashyaka was born in 1963 in Butare, Rwanda. Since 1989, he has been living in exile in Germany. In 2000, Germany granted him political asylum.
He was arrested in Germany in 2006 for immigration violations and released shortly after.
In 2008, Germany withdrew Murwanashyaka's refugee status.
Along with his vice-president Straton Musoni, Murwanashyaka was arrested on November 17, 2009 in Germany, on the basis of an arrest warrant issued by the German Federal Court of Justice.
The German federal prosecution had been actively investigating the two men for more than a year, who were then on Interpol red notice.
On December 8, 2010, the German Federal Prosecutor charged Murwanashyaka and Musoni with 26 counts of crimes against humanity and 39 counts of war crimes, allegedly committed by the FDLR on Congolese territory between January 2008 and November 2009.
Murwanashyaka and Musoni were accused of ordering and co-coordinating crimes committed by the FDLR from German territory and for not having prevented their commission.
Murwanashyaka was also accused of leading a foreign terrorist organisation.
FDLR is on offshoot of the forces that committed the 1994 Genocide against the Tutsi, which claimed over a million lives.