A British man has had both legs amputated and is in critical condition after being hit by a trailer truck in a horrendous hit-and-run in Thailand.

William Braid, 54, was riding his Yamaha motorbike in central Bangkok on July 27 when he veered and fell into the road. Moments later, a 20-wheel truck drove over his legs and sped off without stopping.

The retired teacher, originally from Arbroath, Scotland, suffered devastating injuries.

Friends say William, known to many as Willie, urgently needs A-negative blood to survive. The rare blood type is found in just 70,000 of Thailand's population, and supplies have already run out.

His friend Ava Vora said: 'Willie's blood type is very rare in Thailand, just 0.1 per cent of people have A Negative. The doctors have run out of blood donations for him.'