Ranchi, Aug 3 - The Central Bureau of Investigation (CBI) Monday filed graft cases against senior Indian Administrative Service (IAS) official who had served as an aide to former Jharkhand governor Syed Sibte Razi.

Two cases of disproportionate assets were lodged against Avinash Kumar, officer on special duty (OSD) of Razi, said a CBI official.

CBI sources said the raids were conducted after some complaints. The CBI has not come out with any official statement on the raids yet.

According to CBI sources, the raids were conducted simultaneously at houses of Kumar and Rajesh Thakur, who was Razi's personal secretary since he took over as governor in 2004.