Mother and daughter in 'assassin's poison' scare

An American mother and daughter rushed to hospital in Moscow for suspected thallium poisoning arrived home today as colleagues and relatives struggled to understand how they could have been exposed to the potentially fatal chemical.

Dr Marina Kovalevsky, 49, and her daughter, Yana, 26, arrived at Los Angeles International Airport aboard an Aeroflot flight and were taken in wheelchairs past reporters to two waiting ambulances.