Helen Golder of Hoghton, near Preston, was among those who died when the 10 seater Toyota vehicle crashed on June 30 last year.

The tyre which burst was in 'poor condition' and looked unlike the other three tyres on the vehicle, the Gloucester inquest was told.

The vehicle had been hired at the last minute by a local tour operator because the scheduled minibus had not returned from a service.

After the tragedy, the owner of the tour company admitted the bus had not had any safety checks before the trip.

Gloucestershire coroner Alan Crickmore recorded accidental death verdicts on Ms Golder, 33, and colleagues Elizabeth Wilson, 31, from London and Susan Andrews, 32, of Naunton Lane, Leckhampton, Cheltenham.

All three were working as volunteers for heart specialist Sir Magdi Yacoub's charity Chain of Hope, which performs cardiac surgery in developing countries, the inquest was told.

When tragedy struck they were on a trip from the capital Maputo to the Kruger National Park in South Africa.

At the time of the crash Ms Golder, a former pupil of Gregson Lane Primary School, Walton-le-Dale High School and Runshaw College, Leyland, was employed by the Royal Brompton & Harefield NHS Trust. She had been working in London for three years.