Police have been caught going too fast in their quest to snare speeding drivers.

Sussex Police have been forced to apologise to scores of motorists they told would be prosecuted after staff realised they did not have Government approval for the equipment they were using.

Each of the drivers who was photographed will now have their fines quashed because the force has discovered evidence recorded by the new kit is inadmissible in court.

Those who have already paid the sums will have them reimbursed, while any penalty points they were given will be wiped off their driving licences.

But drivers’ groups said people who had already suffered the consequences of the fines – such as losing their jobs after being banned from the road – could consider suing the force.

It was six weeks before the gaffe was spotted.

The problem arose when a mobile camera was fitted with an updated DVD recorder called Concept 2 in November.

The equipment has not yet been approved by the Home Office, which carries out rigorous tests on devices used by police before they can be relied on to provide evidence in court.

The images recorded by Concept 2 could have been used in court if supported by an officer’s testimony, but not on their own.

Instead, about 200 drivers are receiving letters from Superintendent Lance Gray, head of Sussex Police’s criminal justice unit, apologising for being sent speeding tickets which threatened them with at least £60 fines and three penalty points on their driving licences.

Drivers who get 12 points on their licence face an automatic ban.

Supt Gray’s letter read: “This one item of equipment is an upgrade to the existing equipment, which does have type approval.

While not critical to the validity of the evidence obtained, Sussex Police take the view that to maintain public confidence it would not be appropriate to prosecute in your case.”

One driver, who was told he had been caught speeding while travelling under the Broxmead Lane overbridge on the A23 at Bolney on December 5, said: “They shouldn’t really have been using a machine that was not acceptable.

“It is pretty embarrassing and has cost them an awful lot of money.

“I am thrilled I haven’t had the three points on my licence.”

Hugh Bladon, of the Association of British Drivers, said people on nine points, who might have lost their job because of an automatic driving ban, could be in line for compensation.

He said: “There is an awful lot more to it than paying back the money.

“The consequences could be awful for someone who needs their car.”

A Home Office spokesman said the Concept 2 equipment was being tested by the department’s scientific development branch.

He refused to confirm whether the kit was likely to be approved or when a decision would be made.