About 4,000 tigers are estimated to remain in the wild

Crime chiefs from countries with populations of wild tigers have agreed to work together in order to combat the illegal trade in the big cats.

Heads of police and customs from 13 nations agreed to tighten controls and improve cross-border co-operation at a two-day meeting in Bangkok. Only six subspecies remain, with fewer than 1,000 tigers in each group. Smuggling of tiger parts is one of the main threats facing the planet's remaining big cats, say experts.