India, Jan. 9 -- The Enforcement Directorate's (ED) searches on Thursday at the offices of a political strategy firm in Kolkata turned into a pitched political battle with West Bengal's chief minister and Trinamool Congress (TMC) chief Mamata Banerjee claiming it was an effort by the agency to glean intelligence on her party's election strategy and candidates, and the Bharatiya Janata Party, the main opposition in the state, countering that Banerjee was shielding the corrupt and interfering in the lawful functioning of a federal agency.

The matter has now reached the Calcutta high court which will hear it on Friday.

ED said its searches were linked to an investigation of an illegal coal mining racket in the state that found illegal tran...