A family has been left devastated after a much-loved pony was killed in a collision with a car, with the driver allegedly leaving the scene afterwards.

Sofia Carvosso, 20, was walking Paddy, her 14-year-old pony, back to his yard near Dippenhall along a country lane at about 8.30pm on Thursday (June 4) when the collision happened.

The impact threw Sofia to the ground and left her trapped beneath Paddy, who later had to be put down because of his injuries.

Her mother, Abby Carvosso, said Sofia, who rides out racehorses for trainer Andrew Balding at Park House Stables, was wearing high-visibility clothing at the time.

"She heard a car coming," said Ms Carvosso. "It came around the corner very fast, braked, slipped into the hedgerow and then went into the back of the pony.

"Sofia fell to the ground and was underneath him screaming for help."

Ms Carvosso said the driver stopped briefly before leaving the scene.

"Sofia, who escaped without serious physical injury, managed to call me from beneath the stricken pony," she said.

"He left the scene not knowing whether my daughter was alive or dead."

Paddy later managed to get to his feet, which Ms Carvosso believes may have saved Sofia from more serious injury. However, the pony's injuries were so severe that he was euthanised at the scene.

The family had owned Paddy for about eight years, since Sofia was 12. Ms Carvosso described him as "the pony of a lifetime".

"He was the pony that every little girl wants to have," she added.

A Pony Club Championship and National Schools Equestrian Association winner, Paddy helped shape the careers of several young riders and was well known in equestrian circles.

Despite losing a pony she had grown up with, Ms Carvosso said Sofia had shown remarkable compassion.

"She just wants the driver to know she is OK and hopes he is OK too. But they do have to take responsibility for their actions."

A spokesperson for Surrey Police said officers were still investigating the incident.