Former PM Manmohan Singh has been summoned as an accused along with five others in a case linked to the coal scam that saw mining rights being assigned without any transparency to private firms. A special CBI court has also named Hindalco, its chairman Kumar Mangalam Birla, and former coal secretary PC Parakh among the six accused. They have all been asked to appear in court on April 8. The charges against Dr Singh and the others include criminal conspiracy, corruption and breach of trust.