Exclusive - China's Nanjing Hanrui can't be sure its cobalt did not involve child labour

LONDON/BEIJING - China's Nanjing Hanrui Cobalt, which sells the metal to a firm approved by the London Metal Exchange, said it was unable to ascertain that its products did not involve the use of child labour in Africa.

Nanjing Hanrui is a supplier to another Chinese company, Yantai Cash, which is on the LME's list of firms whose cobalt meets its quality standards.