The former Springboks halfback Joost van der Westhuizen has been diagnosed with a motor-neuron muscle disease.
The South African website Supersport has reported that Van der Westhuizen's diagnosis is regarded as "very serious and could have drastic implications for his health", and his family have asked for privacy.
40-year-old Van der Westhuizen played the last of his 89 Tests in 2003.
