Kolkata, Jan 30 (ANI): TMC leader and West Bengal Chief Minister Mamata Banerjee's close aid Mukul Roy appeared before the CBI, on Friday to face interrogation in connection with his alleged involvement in the Sharda scam. Roy, who also held railway portfolio briefly in the then Prime Minister Manmohan Singh cabinet, denied any wrongdoing. Emerging from the CBI building, Roy said he cooperated with the investigators.