Kumar, lodged in the Puzhal Jail at Chennai, was brought before Judge V Ramasamy who extended the custody.
Earlier, Kumar gesticulated angrily at photographers and TV cameramen who thronged the area before police officials pacified and took him inside the court.
The CBI court had dismissed his bail plea on May 11.
Kumar, then IGP (West Zone) here when the case was registered, was arrested in New Delhi on May 2 on the charge of entering into a conspiracy to get a bribe of Rs 10 crore from Paazee Forex Trading company for protecting its directors facing charges of duping depositors of Rs 826 crore in 2009.
He has been charged with abusing his official position and making his subordinates and accomplices extort money from Paazee Group of companies to safeguard its directors.
He was on the run for a long time and the Madras High Court had turned down his anticipatory bail plea last month.
