The agency wants to question Kumar, a 1979-Batch IPS officer of Manipur-Tripura cadre, as it claims to have evidence about his alleged involvement in the conspiracy.
The sources said the officer had claimed in his defence that the intelligence input given by him which led to the encounter was a genuine one and giving input does not mean that he directed the police to carry out the encounter.
Gujarat police had alleged Ishrat was part of a terror outfit LeT module aiming at the life of Gujarat Chief Minister The sources said, however, that the agency was not concentrating merely on the intelligence input and that they have enough leads which indicate Kumar's alleged involvement in the conspiracy leading to the encounter found to be fake by the Special Investigating Team constituted by the Gujarat High Court.
The sources said the focus of the agency's probe has been whether intelligence officers were active participants in the conspiracy behind the killing Ishrat.
CBI's move to question Kumar had strained its relations with IB and Union Home Secretary R K Singh had to convene a meeting of CBI Director Ranjit Sinha and IB Chief Asif Ibrahim to discuss the issue in detail.
CBI had issued fresh notices to the officer under the provisions of the Code of Criminal Procedure as previous examination of the officer was not satisfactory and replies given by him, the agency said, appeared diversionary.