Bharatiya Janata Party (BJP) chief Nitin Gadkari today slammed the Congress-led United Progressive Alliance (UPA) government for the alleged “misuse” of the Central Bureau of Investigation (CBI) as a “tool against its adversaries”. Mr Gadkari told reporters in Mumbai that the CBI is a political arm of the UPA government. His comments followed CBI's decision to arrest former Gujarat minister of state for home Amit Shah in the 2005 killing of Sohrabuddin Sheikh.