A man will appear in court in connection with a letter sent to a force's most senior officer which caused concern for the safety of councillors and election candidates.
A 39-year-old man from Lanchester, near Durham, has been charged with one offence of "malicious communications."
It follows letter which was sent to the Chief Constable of Durham, Mike Barton, which arrived at the force's HQ in Aykley Heads on February 28.
The force has said that within the letter, there were the names of 57 Labour Durham County Councillors.
The letter stated that “contracts” involving varying sums of money had been taken out on each of them, this also applied to any other prospective candidate standing for the Labour Party at the forthcoming May elections.
In the aftermath of the letter's arrival, Durham Constabulary said: "Inquiries are taking place to trace the person responsible for the letter and we are liaising with Durham County Council to offer reassurance to those named."
The man, who has not been named, has been bailed to attend Peterlee Magistrates' Court at 2pm on May 16.