Gill Whitmore is contesting a penalty of a fine and six points after she was clocked twice by a mobile camera doing 38mph in a 30mph zone in Ryhope Road, Sunderland.

The 45-year-old had travelled about three quarters of a mile up and down the road and bought a breakfast at the drive-through restaurant in 3mins 23secs, according to a police speed gun.

Driving campaigner Neil Herron heard about Miss Whitmore's case and tested the same route using equipment designed by South Shields scientist Dr Phillip Tann, and he claims the quickest time possible is 5mins 48secs.

Miss Whitmore, who already has six points and would be banned if the tickets are confirmed, is planning to see a solicitor next week to discuss the case.

The single mum, from Waldron Square, Hendon, Sunderland, said: "It is just impossible that I could have driven that distance and been to McDonald's in that amount of time."

She believes the camera is faulty, but Jeremy Forsberg, from Northumbria Safer Roads Initiative, which is responsible for the speed cameras, said the mobile equipment is accurate.

He said: "No one has actually successfully challenged a speed camera in the courts in Northumbria as far as I'm aware. I am totally confident these cameras work.

"If it goes to court, first we will use the judgement of the officer and then we will rely on the evidence of the camera.

"I can't comment on the length of time between the two photos, but these camera record speed accurately."