The Association of Mineworkers and Construction Union (AMCU) on Wednesday called on more whistle-blowers to come forward and provide it with reliable information to further strengthen its legal case against miner Samancor Chrome. The union, together with its partners, law firm Richard Spoor Inc and the Alternative Information and Development Centre (AIDC), have lodged a case of alleged fraud and profit shifting against the miner at the Gauteng High Court.