A vigilante motorist posed as a police officer to pull over speeding drivers, a court has heard.
Martin Goodall, 51, is accused of impersonating a police officer in Bournemouth, Poole and Wimborne in Dorset between January and June this year.
He allegedly attached blue and white flashing lights to the front of a white Vauxhall Combo van, dressed in dark combat trousers and a dark top and wore a police-themed lanyard around his neck before stopping a car.
Goodall, who denies the charges, had quit his role as a volunteer special constable in 1996 after a few months.
But he told Poole Magistrates' Court he had "reaffirmed his oath to the crown" when Charles III became King last year and felt he still had the power to act as a policeman.
The court heard that Goodall was seen pursuing a black hatchback car he claimed was driving at 50mph in a 20mph zone in Poole on 20 May.
But an off-duty special constable drove past his van and thought the flashing lights looked wrong so decided to follow him, the court heard.
Special Police Constable Robert Armadi said: "He said he was a fully attested and warranted special constable of the national vehicle harm reduction unit.
"I asked if he had a warrant card and he said, 'I have my attestation certificate'.”
He added: "I rang 999 to report I had been speaking to someone impersonating an officer.
“He began name-dropping police officers in Dorset Police and said he was a parish councillor in Wimborne."
Goodall denied he had said he was with the National Vehicle Harm Reduction Unit.
He told magistrates he told SPC Armadi he was with the UN police mission and was an ambassador for the National Police Wellbeing Service.
Goodall, from Poole, has pleaded not guilty to nine counts of impersonating a police constable and four charges of using a vehicle fitted with a blue warning beacon, contrary to the Police Act 1996 and Road Traffic Act 1988 respectively.
The case was adjourned until December.
Goodall was released on bail with a condition that he can't be in possession of police equipment or clothing.
Rules on special constables
The court heard from Andrew Turtle, the policing manager for the voluntary sector at Dorset Police, which includes special constables.
Mr Turtle said that special constables give up their police powers when they leave the service.
He said: "Special constables are unpaid volunteer police officers, they have to be recruited, trained and vetted.
"The powers they hold are similar to paid police officers, they remain with the officer while they are in the service. When they retire, resign or leave the force for whatever reason those powers cease.
"They should surrender their warrant card and any accoutrement - Pava [incapacitant spray], handcuffs and uniform."
He added that if someone who left wanted to rejoin they would have to go through the application process again.
District Judge Orla Austin asked him if a special constable could use their powers in a county outside their jurisdiction.
Mr Turtle said: "You do have the powers across all 43 forces in England and Wales but you should really be in uniform to exercise those powers, you need to be able to identify yourself as a police officer.
"It's not something you would do, just go out and stop vehicles out of uniform out of your home county."
What is the Police Act 1996
The Police Act 1996 sets out the powers and responsibilities of police forces in England and Wales.
It outlines the powers of police officers to stop and search individuals, seize property and use reasonable force when necessary.
The act establishes the role of the relevant police authority in overseeing the work of the police and provides for the appointment of chief constables.
It also deals with the regulation of private security firms and the licensing of public entertainment.