A car-mad baby who knows how to start a car, put it in gear and remove the handbrake caused panic when he stole his mum's car keys and locked himself in her Mercedes with their ten-stone dog yesterday.

Police were forced to smash the car window to free Magnus Sandbach, who is 19 months old, and has now earned himself the nickname Little Stig after the incident in Kingston Hill.

His mum Anna Osborne, 32, called the police because she knew he was capable of starting the car and said he is so intelligent that it was only a matter of minutes before he worked out how to drive the automatic C-class down the road.

She said: "I was telling him to press the button and unlock the car, but he was just waving the keys and laughing.

"He's now naming all the car makes.

"He's obviously got a strong boy gene. He watches Top Gear as well - anything with cars and trains."

Mrs Osborne's main concern was how their four-year-old cane corso Presley, who was in the boot, would react.

She said she is a gentle soul, and training to be a therapy dog, but she was concerned how it would react when police broke in because its instinct would be to protect Magnus.

Luckily it was not perturbed and after barking at Kingston officers PC Simon Burge and PC Mark Sexton, one of which is scared of dogs, went back to sleep.

Mrs Osborne said she would have to get a spare set of keys cut in case he decided to pinch them from her handbag again.

She said: "I think we are going to have to get him his own car - it's the only way forward.

"He is a real tinker - handbags, anything he shouldn't have, he tries to get hold of. He will probably be hanging off the window sill when your photographer arrives."

Mrs Osborne admitted she was partly to blame for his car knowledge, after showing him how the engine starts, but apportioned some blame to his ten-year-old sister Leyla, who often sits in the car with him to listen to the radio.

She said: "He just absolutely loves the car. If you put him in his baby seat, he wriggles out of it because he wants to drive. He really is something else.

"When the police got him out, he looked slightly abashed, but a minute after he was trying to get the car keys back."