Police are reviewing their use of laser speed guns in south Kent after a court case where it was found an officer had failed to set up the device properly.
The review only applies to hand-held laser speed guns
The gadgets have been out of service while the county's force ensures they are operated correctly.
Police chiefs have ordered there should be no more fixed penalties or summonses issued from using laser guns while the review takes place.
But drivers are warned static and mobile cameras will still be used.
Sgt Lynne Castle said: "It was identified through a court case that the set-up procedure [used] for the device in question was incorrect, not the accuracy of the device.
"The speed, distance and alignment checks the manufacturer requires prior to use weren't carried out correctly by an officer, therefore the device shouldn't have been used."
A force statement said: "Hand-held laser guns are used at local level in response to community concerns about speeding and road safety.
"Their use has been temporarily withdrawn in the south Kent policing area following a recent court case, to ensure that officers are aware of and follow the appropriate policy and manufacturers instructions for their use."
The review is expected to be completed in about a week's time.
Sgt Castle admitted that some motorists may feel they could now challenge previous speeding fines.
But Jeanette Miller, president of the Association of Motor Offence Lawyers, said: "Reopening historical cases would undoubtedly involve a struggle as I doubt the courts will be happy to entertain a 'floodgates' situation on the basis of one officer's failings."
Miss Miller added that Kent Police's policy review was "to be commended as they have clearly identified a training need that, if left unaddressed, could lead to unsafe convictions".
A statement issued by the Association of Chief Police Officers said: "Following the outcome of the court case in Kent, there are no questions surrounding the technology used in the case in question.
"The issue highlighted in the court case was simply that the operator was unable to prove the distance measurement as part of the pre-enforcement checks that take place prior to a patrol.
"There are no issues over calibration and the device as all lasers devices can be safely relied upon."