The appointments committee of the cabinet headed by PM Manmohan Singh had cleared their names in November.
After clearance from the appointments panel, Ibrahim was appointed as an officer on special duty in the IB. Ibrahim — the first Muslim to hold the top post in IB — took over from Nehchal Sandhu, who retired on Monday.
Before becoming the IB chief, Ibrahim was serving as the special director in the organisation after his return from London where he held the post of minister (coordination) in the Indian high commission.