An Iranian woman who was sentenced to death by stoning for adultery is to be hanged for murder instead, according to a human rights group. Skip related content The German-based International Committee Against Stoning said Sakineh Mohammadi Ashtiani is to be executed today. "The authorities in Tehran have given the go-ahead to Tabriz prison for the execution of Iran stoning case," the group says on its website. "It has been reported that she is to be executed this Wednesday, November 3." Foreign Office minister Alistair Burt called Iran's charge d'affaires in London to ask if the report was accurate. But the Tehran diplomat was unable to confirm or deny the claim, the Foreign Office said. Mr Burt said in a statement: "I took the opportunity to remind him the UK Government would regard the execution of Ms Ashtiani as utterly unacceptable." Ms Ashtiani's case has provoked a worldwide outcry with leading political and religious figures condemning her original sentence as medieval and barbaric. Brazil, a close ally of Iran, has offered to give the 43-year-old mother of two asylum. In September, officials said Ms Ashtiani's adultery conviction was under review, but she still faced a charge of being complicit in her husband's murder. Iranian television had previously aired an interview with a woman it said was Ms Ashtiani admitting to a relationship with a man who then killed her husband. The International Committee Against Stoning called the TV show "toxic propaganda". The case has worsened relations between Iran and the West, already strained by a dispute over Tehran's nuclear programme. According to Amnesty International, Iran is second only to China in the number of executions it carries out. It put to death at least 346 people in 2008.