LONDON — BBC chief Tony Hall is receiving around-the-clock protection after he received a death threat linked to his sacking of “Top Gear” presenter Jeremy Clarkson, according to reports.

Hall, the broadcaster’s director general, received an email containing the threat on Wednesday. London’s police service, which is investigating the threat, said the email appeared to have been sent from outside the U.K.

According to the Mail on Sunday, the BBC sought to hire an eight-man security team on Wednesday. A vehicle from a security company, London Protection Services, was stationed overnight at Hall’s home in Oxfordshire. The company’s bodyguards are all former members of the military or police.

Hall decided on Wednesday not to renew Clarkson’s contract, after the “Top Gear” host allegedly attacked the show’s producer Oisin Tymon while they were on location in Yorkshire, Northern England. According to Hall, Tymon had to be treated at a local hospital “after a physical altercation accompanied by sustained and prolonged verbal abuse of an extreme nature.”

Hall said Wednesday: “For me a line has been crossed. There cannot be one rule for one and one rule for another dictated by either rank, or public relations and commercial considerations.”

Since the alleged attack, the show has been off air, and Hall has asked BBC exec Kim Shillinglaw to look into how the broadcaster can “renew” the program.

Tymon has been the subject of violent threats on social media since Clarkson’s dismissal.

“Top Gear” has an audience estimated at more than 350 million in 214 territories worldwide.