Police dismissed a telephone call claiming responsibility for the murder of Jill Dando in revenge for the NATO bombing of Serbian TV headquarters, a new documentary claims.

It has emerged that a man with an east European accent made a call within hours of the murder of the broadcaster on the morning of 26 April 1999, in which the killing was linked to the bombing in Belgrade three days earlier, when more than a dozen civilians died.

According to a summary of the message found by the ITV documentary the caller said: “Re the murder of journalist tell your Prime Minister in Belgrade 15 killed so 14 more to go.”

It is not clear whether the call was made to the BBC, where Ms Dando worked, but it was passed to detectives by 3pm on the day of her death.

Two further phone calls came in the days that followed, also appearing to claim responsibilty for the murder.

But these appear to have been dismissed or not followed up by Metropolitan Police officers investigating Ms Dando’s killing outside her home in Fulham.

The claims will once again raise questions about the police investigation and the failure to find the killer responsible for her death 20 years on.