The Democratic Republic of the Congo (DRC) must bring to justice those responsible for the murder a human rights defender five years ago, Amnesty International and Minority Rights Group International said.
Pascal Kabungulu, a prominent human rights activist, was killed on 31 July 2005 by a group of armed men who broke into his house in Bukavu in eastern DRC, dragged him out of his bedroom and shot him dead in front of his family.
The trial of the men accused of killing him, who include a Colonel in DRC's armed forces, has been deadlocked since December 2005.
"President Joseph Kabila made a public and personal commitment in 2006 that justice would be done in the case of Pascal Kabungulu," said Claire Morclette, DRC campaigner at Amnesty International.
"The fact that Pascal's wife and six children have had to flee the country and yet his killers remain free makes a mockery of this promise."
In a joint letter to the Congolese Minister of Justice and the Minister of Defence, the two human rights organizations pressed for a speedy resumption in the trial of Pascal Kabungulu's alleged killers, last adjourned in December 2005.
After an investigation into Pascal's murder, a number of soldiers were arrested and a military tribunal opened in late November 2005. It was suspended after evidence emerged that more senior political and military figures may have been involved in the killing.
The ruling of the military tribunal was that a higher military court had to hear the case, but no date has been announced for the new trial.
While some of the accused have remained in detention since 2005, the senior figures alleged to be involved in Pascal Kabungulu's death remain at large, including a brigade commander of the Armed Forces of the DRC (FARDC). The commander in question has not even been suspended from duty.
"Pascal's family have waited too long to see justice done," said Carl Soderbergh of Minority Rights Group International.
"Other human rights defenders in the DRC will remain at risk if senior figures in the army and in government are seen to act above the law."
The body of another leading human rights defender, Floribert Chebeya Bahizire, was found bound in the back of his car in Kinshasa on 2 June 2010.