Béatrice Munyenyezi was stripped of her US citizenship after she was convicted in 2013 – she had already spent nearly two years in custody.

She had settled in the US in 1998 with her three daughters, saying she had been persecuted in Rwanda.

About 800,000 people, mainly ethnic Tutsis and moderate Hutus, were slaughtered in Rwanda in 100 days in 1994 by Hutu extremists, many of whom later fled the country.

Prosecution witnesses had told of how Munyenyezi had inspected identity cards at a notorious roadblock where ethnic Tutsis were singled out for slaughter.

She had also denied affiliation with any political party when she applied for asylum, despite her husband being a leader of the Interahamwe militia – the youth wing of the then-governing MRND.

The 51-year-old is expected to be arrested on her arrival home and charged over her role in the genocide.

Her husband, Arsène Shalom Ntahobali, and her mother-in-law, Pauline Nyiramasuhuko, who was a government minister, were both found guilty in 2011 by the UN International Criminal Tribunal for Rwanda for their role in the genocide and are serving long prison sentences.