Hundreds of thousands of motorists caught speeding might be able to claw back points they lost on their driver's licence and penalty fines they were charged – because police distributed the tickets illegally.

The blunder involved an employee at Essex Police who has been sending out penalty letters to motorists caught speeding without authorisation from a Chief Constable, which is a requirement under the Road Traffic Offenders Act 1988.

Reports have suggested that the blunder could lead to compensation claims worth a total of up to £50 million from drivers who have received the notices over the past four years.

However, Donna Veasey, a spokeswoman for the force, said: "It should be stressed that even if this does prove to be an issue it would only affect a proportion of cases where the person went to magistrates' court since March 2007.

"It would not affect the vast majority of the cases the bureau deals with, including fixed penalty notices or taking part in the driver improvement scheme, rider improvement scheme or speed awareness course."

Aidan Carr, partner at Rowlands who specialises in motoring cases comments: "Sometimes cases can be won on technicalities – so called 'loopholes' – but this requires specialist knowledge of procedures.

Motorists can lose their jobs and sometimes their houses if disqualified and so it is important to consult a solicitor at the earliest opportunity".