New Delhi, May 21 : The Central Bureau of Investigation (CBI) has lodged a case against a senior trade instructor (STC/NBQ) and a stenographer, both posted with Northeast Frontier Railway (NFR) for allegedly demanding "a bribe" from a female co-worker to regularise her leave, an official said. A senior CBI official added that a complaint in this connection was lodged by one Ranjit Mondal, a resident of Goalpara, Assam. Mondal alleged that Lakhindar Prasad, the STC, allegedly demanded illegal gratification to regularise the leave of one Shruti Sangma, who works as technical staff with the NFR. "The allegations were verified and prima facie it was found that there was a joint demand of illegal gratification on the part of Lakhindar Prasad, and Ramesh Kumar Ranapaheli, another employee of NFR. They instructed the complainant to make the payment by Saturday," the official said. After completing the preliminary investigation, the CBI lodged a case under sections 120B of the IPC and Section 7 of the Prevention of Corruption Act. Further investigation in the matter is underway. /IANS