Extra security checks and guards were in place at the BBC's main centres in London and Mr Hall was put under police protection. He was given a police guard after someone claiming to be a Serb telephoned the corporation switchboard, saying he was behind the killing of the Crimewatch presenter, and that Mr Hall would be next. The caller said that Ms Dando's killing was retaliation for the Nato bomb attack on the Serbian television centre in Belgrade last week.
Ms Dando, 37, was killed by a gunman who shot her once in the head at close range on Monday outside her south-west London home. Police are still searching for a motive for the killing. The explanations considered most likely are an attack by a stalker or person bearing a personal grudge, or a hit by a professional killer.
The BBC is reviewing whether it should be giving extra protection to staff who appear on screen. High-profile security was in place at fourBBC centres in London yesterday - at White City and the neighbouring television centre, Bush House, home of the World Service, and Broadcasting House. Security guards were turning out bags and checking BBC identity tags of everyone arriving at Broadcasting House. A spokesman said: "It is not unusual for there to be threats to presenters or people in the BBC."
The corporation's head of security has advised staff to report "any suspicious incidents involving unsolicited phone calls, letters or any other type of communication.
"At home, it is recommended that people do not answer the door unless they can identify the visitor," said the chief investigator, Eddie Halling.
The security measures were introduced as the parents of Ms Dando's fiance, Alan Farthing, paid tribute to the television presenter, describing her as a "fantastic and loving person".
In a statement issued yesterday, Dr John Farthing and his wife, Barbara, said: "We shall miss her, and the tears testify to that, but we shall never forget her or the light she brought into our lives."