|The Fugitive Gen Kayumba Nyamwasa|
Lieutenant-Colonel Rugigana Ngabo was seized by military police on Friday and is being detained at a military prison, an army spokesman told Reuters late on Monday.
"People are saying there is a crisis. There is no crisis in the Rwandan army. Ngabo was arrested because he was engaged in matters of insecurity. The RDF (Rwanda Defence Force) is a professional army which doesn't tolerate indiscipline," Lieutenant Colonel Jill Rutaremara told Reuters.
Ngabo is the brother of General Faustin Nyamwasa, a critic of President Paul Kagame that fled his homeland in February and was shot in the stomach in June while in exile in South Africa.
The RDF said Ngabo's arrest had nothing to do with his relationship with Nyamwasa.
Kigali wants Nyamwasa back home to answer to charges of alleged terrorism in connection with grenade blasts that rocked the country this year. He has denied the charges.
Media reports quoted Ngabo's wife as saying she did not know where her husband was being held.
"Because of the sensitivity of the investigations at the moment we are denying access. He is not hidden, he is not hostage, he is being held in military police custody in Kanombe," Rutaremara said.
He said he would appear before a military court soon.
Kagame was re-elected for another seven-year term this month in elections that human rights groups say were clouded with intimidation and violence.
In the run up to the poll, a local journalist was shot dead and an opposition official was found nearly beheaded in July.
Despite being poor in natural resources, Rwanda is a rising star in Africa for donors and investors. (Editing by Alison Williams)