The Federal Criminal Police said in a statement that the 53-year-old, who belonged to the Hutu ethnic group, had been the mayor of a municipality in the north of Rwanda and had ordered three massacres.

The federal prosecutor in Karlsruhe said Monday that at least 3,730 people were killed in those massacres – part of the 1994 genocide by Hutus against the Tutsi ethnic group, in which at estimated 800,000 Tutsis were killed, most of them by clubs and machetes.

The man came to Germany in 2002 as a refugee. He was previously arrested in 2008, but the Federal Court overturned the arrest warrant because it rested primarily on hearsay evidence. A new warrant has been issued after intensive investigations over recent weeks.