Ms Niyongere was the deputy leader of the women's wing of the main opposition Congress for Freedom (CNL) party in Kiganda commune.
Burundi's opposition politician Marie Claire Niyongere was sexually assaulted before being killed and her body dumped in a forest, a local administrator has told the BBC Great Lakes.
Ms Niyongere was the deputy leader of the women's wing of the main opposition Congress for Freedom (CNL) party in Kiganda commune.
Her body was found in a forest on Tuesday with injuries on the neck and genitals, Kiganda commune administrator Celine Ndabubaha said.
Ms Ndabubaha said one man who is suspected to have committed the crime is still at large.
CNL spokesperson Terence Manirambona said the politician was “killed in a shocking way”, but that the party is yet to know the motive of the murder.
Ms Niyongere, who has left four children, will be buried on Friday, Mr Manirambona said.
CNL has been denouncing violence against its members ahead of the 2020 presidential elections.
In August, another party member, Nsavyumwami Gregoire, was killed in an attack by a group of people who were armed with machetes. The suspects are facing trial.
A report released in September by the UN Human Rights Council found “serious human rights violations in Burundi against members of the opposition and their families perpetrated by government forces and the governing party's youth wing, Imbonerakure.