Fulgence Kayishema, who is accused of involvement in the genocide in Rwanda in 1994, has been arrested in Paarl, South Africa.
Kayishema is one of the four individuals considered to bear primary responsibility for the estimated 800,000 people who were killed in Rwanda during the spring of 1994.
In a statement, South African police describe Fulgence Kayishema as "one of the world's most wanted for genocide."
The genocide in Rwanda was led by extreme nationalists from the majority Hutu ethnic group. Most of the victims were from the minority Tutsi ethnic group, but Hutus who were seen as accomplices were also killed.
Fulgence Kayishema, som anklagas för inblandning i folkmordet i Rwanda 1994, har gripits i Paarl i Sydafrika.
Kayishema är en av de fyra personer som anses bära huvudansvar för att uppskattningsvis 800 000 människor mördades i Rwanda under våren 1994.
I ett uttalande kallar sydafrikansk polis Fulgence Kayishema för "en av världens mest eftersökta personer för folkmord".
Folkmordet i Rwanda leddes av extremnationalister från majoritetsfolket hutu. De flesta offren tillhörde minoritetsfolket tutsier, men även hutuer som sågs som medlöpare mördades.
