A group of British police officers who pulled over a speeding car ended up facing a newborn baby instead of a criminal as a heroic grandfather delivered his granddaughter at the side of the road.

Lola Mia Rose was born just as seven officers in four unmarked cars, who had chased her grandfather Colin Ellmore at speeds of 160km/h along the M275 in Portsmouth, surrounded the car.

Her mother Tiffany, who has three other children, described the experience as “quite scary” and said she was “very proud” of her dad for delivering baby Lola.

After suffering some “niggling pains” throughout the day the 26-year-old, from Fareham, said she realised at around 9.55pm that she needed to get to the hospital.

Accompanied by her partner Steven Read, their seven-year-old son Ralphy, and her parents Colin and Elaine, the family made their way towards the Queen Alexandra Hospital in Cosham.

“My dad came to pick us up and before I got into the car I said to him ‘I need to push’,” said Tiffany, who was 38 weeks pregnant when the birth happened on Friday night.

“As the car was moving my waters went, then the police pulled us over and my dad came round and opened the door. I knew she (Lola) wasn’t going to wait and then suddenly her head started to appear.

“The whole thing was quite scary.”

Lola, who weighed 2.8kg, and her mother were transferred to the hospital by ambulance soon after and discharged on Saturday.

Despite her dramatic entrance into the world Tiffany said her fourth child is doing well.

“She’s doing great,” she said. “She’s been very good.”

Sergeant Simon Goss said they thought the car might have been stolen because it was being driven so fast.

“We initially thought it was a stolen vehicle so put our lights on to flash it down. But it kept going at the high speeds,” Mr Goss told the Portsmouth News.

“We boxed it in, forcing it to stop, and when it did the driver got out and we thought he was running off.

“But he ran around the car to the passenger side and shouted something about a baby. When we got to the car, we saw the baby in the man’s hands. I have never experienced anything like it before.”

Police said no action would be taken over the incident.