Pregnant Denise Lewis in carjack terror as she picks up daughter from school

The former athlete, 35, who is pregnant with her third child, was driving a £25,000 Volkswagen Golf when it was deliberately rammed from behind.

As she got out to check the damage, a man in the passenger seat of the car which had hit her leapt into the Golf, started the engine and sped off, also taking her handbag.

Denise grabbed the car door and tried to run alongside it, injuring her arm, but she had to let go when she couldn't keep up.

Yesterday she said the incident, which happened in the affluent Buckinghamshire village of Farnham Royal, had left her frightened but relieved neither of her children were harmed.

She said: "I was pretty shaken. It was the middle of the day on a quiet residential road so you just don't expect something like that to happen.

"I'm just thankful I didn't have my two-year-old son Ryan in the back seat that day as I often pick him up from nursery before picking my daughter up. If he had been in the car I don't know what would have happened to him.

"And, of course, because I'm expecting a baby, that brought a lot of fears to my mind after the event too – at the time there was too much adrenalin pumping for me to consider what could have happened.

"I hurt my arm as I grabbed hold of the car door as it was speeding off but I've been checked by my GP and I'm fine."

The carjacking took place at around 3.30pm on Thursday as she drove the black Golf R32, belonging to her property developer husband Steve Finan, 43, to pick up six-year-old Lauryn – her daughter from a previous relationship – from school.

The country road it lies on is typical of the upmarket area in which she and her family live.

Denise, who won gold in the heptathlon at the 2000 Olympics, said: "I was approaching the school and realised another car, a silver or pale blue hatchback, was following me.

"I thought, 'Why are you so close?' It felt like an accident was about to happen.

Shaken The former athlete with her daughter Lauryn, now six, in 2004

She got out and walked around to the back of her vehicle to see what damage had been done and with the intention of talking to the driver, whom she describes as a white man aged between 20 and 25.

Then she noticed his passenger, a slightly older Asian man, get out.

"He darted past me and I heard my engine rev. I ran to the driver's side of the car and got hold of the door which was still open.

"I was going to ask him what on earth he was doing. Then he sped off.

"I tried to keep hold of the door, but even I can't keep up with a car like that.

"At the same time, the car which had rammed me sped off too."

Staff at the school heard the screeching of tyres and came out to comfort Denise, while she called the police.

She has had to change the locks on her home and deal with the inconvenience of losing personal items but she doesn't believe she was targeted as a celebrity because the car she was driving had tinted windows to protect her privacy.

She added: "I'm a pretty strong character so I won't be put off driving. I would just urge people to think twice before getting out of their car if something like this happens to them.

"Just sit there for a few minutes longer than you would normally and call the police."

A spokesman for Thames Valley Police said: "We are investigating this incident and would urge people with any information relating to it to come forward."

• Denise Lewis is not the first celebrity to have fallen victim to car crime. A £50,000 Range Rover owned by Kate Moss was targeted by robbers in Belsize Park, North London. The supermodel's nanny, who was driving, had briefly got out of the vehicle to allow Kate's three-year-old daughter Lila Grace to answer a call of nature.

Seizing the moment, thieves dived into the car and made off with the nanny's handbag, cash and credit cards.

Footballer Frank Lampard was woken at 4.30am by the roar of engines as two of his cars – a Mercedes 4x4 and an Aston Martin – were taken by a gang who had taken the keys in a burglary on his home in the capital.

And Socialite Tara Palmer-Tomkinson's BMW 6-Series was stolen from outside her home in Kensington, West London, by a gang who had followed her home.