NHS driver William Seeney was killed when a black racehorse galloped out of the darkness and hit his lorry on a main road, an inquest heard.

The 49-year-old from Dovehouse Close, Eynsham, died instantly from the injuries he suffered in the head-on crash on the A40 at Andoversford, near Cheltenham, on April 7 last year.

Gloucestershire assistant deputy coroner Katy Skerrett said it would never be known how the pregnant mare called Mistress Cool managed to escape from her field and get on to the busy main road.

Recording a verdict of accidental death she said Mr Seeney, who was married with two children, was in good health. She said: “This collision was absolutely unavoidable.”

Such was the force of the impact that Mistress Cool’s unborn foal was later found on the verge, leading police to wrongly assume it had been born prior to the accident.

Crash investigator PC Dave Holland said that, assuming that Mr Seeney had dipped headlights, he would only have been able to see for about 50 metres.

The coroner said: “We will probably never know how she got on to the A40.

“On the face of it there is no clear error by the owners.”