Demanding a Joint Parliamentary Committee (JPC) probe, senior Supreme Court advocate Prashant Bhushan on Sunday said here the Rafale fighter aircraft deal as India's largest defence scam.Bhushan said the deal compromised the national security as the number of fighter aircraft contract had been reduced to 36 from originally planned 126.Speaking to reporters here, Bhushan said the central government should order a JPC probe into the deal.He said the deal compromised the national security and also denied Hindustan Aeronatics Ltd (HAL) a chance to acquire technology to manufacture fighter aircraft.Bhushan also charged that the central government by-passed the set procedure in the purchase of defence equipment.According to him, the Defence Ministry, IAF and the Ministry of External Affairs were kept in the dark about the deal.