No premises of the CM or his family are being covered, they said.
The federal agency few weeks back had filed a enforcement case information report (ECIR) to book the CM and others taking cognisance of a recent Lokayukta FIR, the sources said.
The CM is facing allegations of illegalities in the allotment of 14 sites to his wife by the MUDA.
Siddaramaiah, his wife B M Parvathi, brother-in-law Mallikarjuna Swamy and Devaraju — from whom Swamy had purchased a land and gifted it to Parvathi — and others have been named in the FIR registered by the Mysuru-located Lokayukta police establishment on September 27.
The CM had denied any wrongdoing by him or his family, saying the opposition was “scared” of him and had noted that it is the first such “political case” against him.