A witness due to give evidence at the Birmingham postal ballot-rigging trial said he was too frightened to attend court yesterday after four men disguised in balaclava helmets appeared threateningly outside his house.
Tariq Hussain called the police after noticing a Vauxhall Vectra car speeding up and down Whitehaven Road, Aston, at 10pm on Sunday.
The car stopped outside his house and the men got out before driving off.
Mr Hussain is one of four Liberal Democrat-supporting brothers who helped raise a petition alleging corruption against three Aston Labour candidates during last year's council elections.
The Labour candidates, who were all elected, and their supporters were responsible for the mass forgery of postal votes, claims the petition.
Mr Hussain is alleged to have followed Labour candidates to a warehouse at midnight where postal ballots were stuffed into envelopes.
An election court sitting at the Birmingham and Midland Institute is considering the case, along with a second petition alleging Labour fraud in Bordesley Green.
Richard Mawrey QC, the deputy high court judge sitting as election commissioner, ordered a representative of the Director of Public Prosecutions to investigate Mr Hussain's claims.
However, the incident remained shrouded in mystery last night after the West Midlands Police press office denied having any record of the incident.
But Matthew Brooke, counsel for the DPP, insisted two officers did attend and the incident was recorded on the police log. The officers spoke to witnesses but took no further action, Mr Brooke said.
The court heard that Mr Hussain's brother, Ayoub Khan, one of the losing Liberal Democrat candidates in Aston, has received several death threats since June last year when he began to compile the election petition.
Ravi Sukul, representing the Aston petitioners, told the court: "Mr Hussain has sent a message to me saying that he simply doesn't want to come to court to give evidence."
Mr Sukul said "various incidents" had taken place before polling day last year and Mr Hussain felt he would be inviting further trouble if he came to court.
Mr Mawrey said a witness statement signed by Mr Hussain could be read to the court if he was too intimidated to attend in person.
The judge added: "It would be of assistance if inquiries were made to the police who attended to see what the position was. If the police attended and found large numbers of people in balaclava helmets, I might take a different view."
The case continues.