"The arrest of Felicien Kabuga today is a reminder that those responsible for genocide can be brought to account, even 26 years after their crimes," said Serge Brammertz, chief prosecutor of the Mechanism for International Criminal Tribunals.
Rwandan genocide suspect Felicien Kabuga was arrested on Saturday in the Paris region, the French Justice Ministry said.
Kabuga was living under a false identity in a flat in Asnieres-Sur-Seine, near Paris, and had been pursued by international justice for 25 years, the ministry said in a statement.
French gendarmes arrested him at 0530GMT on Saturday, the ministry said.
The 84-year-old, who is Rwanda's most-wanted man and had a $5 million US bounty on his head.
He is a Hutu businessman, accused of funding the militias that massacred some 800,000 Tutsis and moderate Hutus over a span of 100 days in 1994.
The arrest paves the way for bringing the fugitive in front of the Paris Appeal Court and later to the International Court in The Hague.
A top UN prosecutor said the arrest of the fugitive showed that suspects would be brought to justice for crimes in the 1994 bloodshed.
"The arrest of Felicien Kabuga today is a reminder that those responsible for genocide can be brought to account, even 26 years after their crimes," said Serge Brammertz, chief prosecutor of the Mechanism for International Criminal Tribunals (MICT) in The Hague.
"Today’s arrest underlines the strength of our determination."
The prosecutor praised French authorities, saying the arrest "could not have been made without their exceptional cooperation and skill", and also thanked other countries and international organisations that helped.
Kabuga is now expected to be transferred to the custody of The Hague to stand trial "following completion of appropriate procedures under French law," the statement said.
Kabuga was indicted by the UN International Criminal Tribunal for Rwanda in 1997 on seven counts including genocide.
The Rwanda tribunal formally closed in 2015 and its duties have since been taken over by the MICT, which also deals with cases left over from the International Criminal Tribunal for the former Yugoslavia.
Two other Rwandan genocide suspects, Augustin Bizimana and Protais Mpiranya, are still being pursued by international justice.