The CBI registered a case on August 30, 2005, based on allegations that the assistant postmaster and postal assistant of Guwahati University Head Post Office (GUHPO) entered into a criminal conspiracy with Dutta to cause loss to the public exchequer. In 2003, they fraudulently and dishonestly obtained 50 KVPs. These KVPs were on their way from CSD, Nasik, Maharashtra to CSD, Howrah, West Bengal in 1997-98 and were reported stolen or lost during transit.
Dutta then encashed the KVPs at GUHPO during October-November, 2003 and the loss caused to the government was estimated at Rs 10 lakh. "On June 20, 2008, a chargesheet was filed against Dutta and three others. After hearing the matter, the special judge found Dutta guilty and convicted him," a senior CBI official said.