Police are investigating threats to kill BBC director-general Tony Hall, reportedly linked to his decision to axe Top Gear presenter Jeremy Clarkson. Scotland Yard confirmed it was looking into allegations made on Wednesday, when Hall confirmed he would not be renewing Clarkson’s contract because of his unprovoked attack on producer Oisin Tymon at a North Yorkshire hotel. The Mail on Sunday reported that the director-general – officially crossbench peer Lord Hall of Birkenhead – and wife Cynthia had been under 24-hour guard since the threat was received.