A motorist is set to contest a speeding ticket at court after he says police declined to confirm information he deemed critical to his defence.

Simon Turpin's Volkswagen Golf GTI was recorded at 37mph on a 30mph stretch of road in Melton, near Woodbridge, on June 14 last year.

The 51-year-old had turned onto Wilford Bridge Road from Station Road when clocked by an LTI.20.20 Ultralyte 1000 from a speed van parked 241 metres away beside Melton Primary School.

Mr Turpin, from Stamford, in Lincolnshire, responded to a letter from the Central Ticket Office by requesting photographic evidence of his vehicle at the moment of the alleged offence.

He then followed up by asking police to disclose the maximum distance to which the speed camera was tested.

"The offence is alleged to have been recorded at 241 metres but, to date, the police have only provided a calibration certificate for a maximum distance of 150 metres," he said.

"I have repeatedly asked the police to provide a certificate for the device at or in excess of the distance cited.

"They have refused to confirm whether or not they hold information critical to my defence, and to my ability to decide how to plead."

Mr Turpin travelled to Ipswich on April 1 to deny the offence and now faces trial on July 14.

"I want to clear this accusation because I don’t believe it’s supported by evidence," he said.

"The only way they will reveal whether they have the calibration certificate will be if I go to court.

"My position is clear as it has been constant. Show me the evidence, and if the evidence is there, then I would have pleaded guilty."

Mr Turpin has also complained to the constabulary's professional standards department, but was told his grievance would not be progressed until the completion of criminal proceedings.

While Suffolk police said it could not comment on individual cases, LTI 2020 cameras are said to have an operational range in excess of 750m.

Home Office guidance states that, once checked against three accurately measured distances of between 25m and 100m, the device is authorised for use throughout its approved range.