A court's refusal to convict a police constable who reached 159mph on a motorway of speeding and dangerous driving is being challenged.
Pc Milton was recorded doing 159mph in December 2003
Pc Mark Milton, 38, from Telford, Shropshire, was recorded by the patrol car's video camera on the M54 in 2003.
District Judge Bruce Morgan cleared him after hearing he was "familiarising" himself with a new car.
High Court judges were asked on Tuesday to decide whether an officer could lawfully drive at those speeds.
Edmund Lawson QC, appearing for the director of public prosecutions, asked Lady Justice Hallett and Mr Justice Owen to convict Pc Milton of the charges of dangerous driving and speeding or order a new hearing in his case.
'Eye watering speeds'
He described Pc Milton's driving as "not good for public health" and told the judges that there was no blue lights flashing or sirens sounding when Pc Milton, an advanced driver, was clocked in the early hours of 5 December 2003.
Mr Lawson said: "This case raises issues of real public interest concerning whether a police officer can, with impunity, drive a police car at 'eye watering' speeds in excess of twice the relevant speed limits when not responding to an emergency or otherwise engaged in the prevention of detecting crime."
In the original hearing at Ludlow Magistrates' Court Judge Morgan said Pc Milton, an armed response officer, was the "creme de la creme" of police drivers.
He took into account the fact that two police officers, including West Mercia Police's senior driving instructor, who gave evidence for the prosecution, had declined to classify the defendant's driving as dangerous.
John McGuinness QC, speaking for Pc Milton, said the district judge had been entitled to take account of the officer's advanced driving skills and to conclude his driving was not dangerous at the time in question.
"Excessive speed alone is not a basis to convict for dangerous driving," he said.
A judgement is expected on Wednesday.