A lawyer for independent MP Bob Such has told Adelaide Magistrates Court he wants a hand-held laser made available for independent testing to verify if they are capable of giving incorrect speed readings.

Mr Such is on trial charged with speeding after a motorbike patrol police officer used a hand-held laser gun to clock him at 69 kilometres per hour in a 50 kph zone at Aberfoyle Park.

The MP is challenging the accuracy of the hand-held laser and contesting a $300 fine.

His lawyer Michael Woods told the court the lasers could give incorrect readings if, for example, the beam was aimed at the slanted bonnet of a car or if it reflects off another surface.

Mr Woods told the court the Australian Standards document, with which all officers must comply, specifies the risks of panning or sweeping the laser.

But the prosecution disagreed, saying a laser gun was sophisticated technology and would not give any reading if aimed incorrectly.

Mr Woods said he wanted a copy of the manual and a laser gun for independent testing, requests the manufacturer has repeatedly refused.

The case will be back in court next week.

Michael Woods, for Such, today asked the Adelaide Magistrates Court to consider issuing a subpoena on the laser guns, which he says falsely recorded his client travelling at 69km/h in a 50km/h zone in Aberfoyle Park in 2008.

“They do it (independent testing) in New South Wales, they do it in Queensland, but good old South Australia does not,” Mr Woods said.

He said he wanted a “suitable expert” to do the testing instead of “relying on a so-called expert” presented by the prosecution.

He said he had made “every endeavour” to get access to the laser gun manufacturers instructions but has been denied every time.

Senior Sergeant Fred Wojtasik, prosecuting, said the lasers were “highly sophisticated” pieces of equipment and it was in the “public interest” the technology be protected.

He denied the lasers were capable of giving a false reading as they registered an error code if their operation was in some way obstructed or inconsistent.

The trial, which was due to finish tomorrow, was adjourned to enable the parties to get specific instructions on both the expert’s and the instructions availability.