Rwandan President Paul Kagame has rejected accusations of involvement in the 1994 killing of the country's then president, which sparked genocide.
Mr Kagame said the allegations were politically motivated
Mr Kagame told the BBC that the allegations made by a French judge were scandalous and politically motivated.
He dismissed the judge's statement that only his forces had had missiles capable of downing President Juvenal Habyarimana's plane.
The genocide, in which 800,000 people died, lasted for 100 days.
French legal authorities are investigating Mr Habyarimana's death because his aircraft had a French crew.
On Tuesday, French investigating judge Jean-Louis Bruguiere accused Mr Kagame and his staff of ordering the attack on the presidential plane and called for him to stand trial at the International Criminal Tribunal for Rwanda (ICTR).
Judge Bruguiere is also seeking the arrest of nine of Mr Kagame's close aides - including armed forces chief James Kabarebe and army chief-of-staff Charles Kayonga - over the downing of the plane.
As a head of state, Mr Kagame enjoys immunity from prosecution under French law.
But Mr Kagame told the BBC's Newshour programme that the judge was behaving in an unprofessional manner and that the allegations were not new.
"This is something that has been recycled over the last five years by this French judge, and it's not really a judicial process as such, it's a political process," he said.
He said his Tutsi-dominated Rwandan Patriotic Front (RPF) were not the only ones who had missiles capable of shooting down the plane, which was also carrying Burundi's President Cyprien Ntaryamira.
"There is evidence and there are documents indicating that [the government of] Rwanda had such a missile... and these missiles were probably in the hands of many people in our region and beyond."
Asked who he believed was responsible for the attack, he blamed "those who were where the plane was shot down" - Habyarimana's presidential guard and French troops - and said there had not been a proper investigation.
Mr Kagame has always accused Hutu extremists of killing Habyarimana in order to provide a pretext for the genocide.
Hutu militias blamed the RPF for the killing and started massacring Tutsis and moderate Hutus across the country. The violence ended when the RPF took power.
Mr Kagame has also accused France, a close ally of the old Hutu regime, of training soldiers involved in the genocide.
On Tuesday, Rwandan Foreign Minister Charles Murigande accused France of trying to cover up its complicity.
"The French are trying to appease their conscience for their role in the genocide and are now trying to find someone else to hold responsible for their acts here," he told Reuters news agency.
Defence lawyers for those accused of genocide at the ICTR have backed Judge Bruguiere's call for Mr Kagame to stand trial.
They say Mr Kagame does not enjoy immunity from prosecution at the UN tribunal.