"Because we had fair degree of suspicion that the money he used to get was given by the agencies in Pakistan," Singh said.
Singh is in Thimphu to attend the 4th meeting of the SAARC Interior/ Home Ministers. Fai was arrested by the FBI on Tuesday for illegally lobbying for Pakistan and its spy agency to influence US policy on Kashmir.
Reports also suggested that Fai made donations to US Congressmen and presidential candidates, and organised conferences and seminars to reflect the viewpoint of Pakistan on Kashmir. Earlier, India had refused to comment on Fai's arrest, saying "facts speaks for themselves".