Special Judge Anupam Srivastava rejected the petition, saying there was no need to amend the chargesheet filed by the CBI under section 304 of IPC (culpable homicide not amounting to murder), CBI lawyer A H Khan told PTI.
Culpable homicide is a lesser offence than murder.
Keshavdev had alleged that CBI diluted the charges, as the preliminary police report and FIR filed by Banmore police were under section 302 (murder).
Gurjar is accused of mowing down Singh when the latter tried to stop the tractor-trolley loaded with illegally mined stones and being driven by Gurjar in Morena district of Madhya Pradesh on March 8 this year.
Thirty-year-old Singh was posted as sub-divisional officer of police at Banmore at the time.