The CBI has sought sanction from the Uttar Pradesh government to investigate the alleged role of three senior bureaucrats in connection with alleged irregularities in the investment of over Rs 4,300 crore of provident fund of Uttar Pradesh Power Corporation Limited (UPPCL) employees in scam-hit DHFL and other housing finance companies, sources said. The agency has sought the nod of the state government under Section 17 (A) of the Prevention of Corruption Act which mandates prior sanction from the competent government before initiating any investigation against a government officer.