CPI(M) today demanded an investigation into the role of the Reliance group, which was one of the alleged beneficiaries named in the Volcker Committee report in the oil-for-food scam.CPI(M) General Secretary Prakash Karat claimed that Reliance was one of the biggest beneficiaries along with former External Affairs Minister Natwar Singh and his son Jagat, Andaleeb Sehgal and the Congress Party.The UN-appointed Volcker Committee, which went into the scam, has in its report named Reliance Petroleum as a non-contractual beneficiary in the Iraqi oil-for-food scheme.