"We have already filed our appeal against Ntamabyariro's accomplice, Hategekimana", Spokesperson of the Prosecutor General, Augustin Nkusi, told Hirondelle Agency.
He stressed that there exists sufficient evidence against his former colleague.
The latter, who was prosecutor in 1994, had continued to work in his position after the genocide.
Immediately after the judgement on 20 January, the former minister and his lawyer, Gatera Gashabana, who is also the President of Kigali Bar, had announced that they were going to appeal against the sentence.
Mrs Ntamabyariro was found guilty of various crimes, including incitement to commit genocide, criminal conspiracies and complicity in murders.
Judge Roselyne Ninahazwa of the First Instance Court of Nyarugenge in Kigali concluded that the former minister had financed the assassination of the Tutsi Governor of Butare, southern Rwanda, and Jean Baptiste Habyarimana.
Dismissed by the interim government in mid-April 1994, Jean Baptiste Habyarimana was thrown in prison, then killed after his release from prison.
For the prosecution, Hategekimana, then an officer of the public prosecutor, is an accessory to this assassination for having ordered the prison guards to release the Governor.
But the judge concluded that he had done nothing but carry out Ntamabyariro's instructions which he was unaware of its true intentions.
Arrested in Zambia in 1997, the former minister is the only member of the interim government to be tried in Rwanda.
Her trial began in June 2006.
SRE/ER/MM/SC
© Hirondelle News Agency