Recently CBI team has quizzed Narayanan and Wanchoo as witnesses for its probe into allegations of bribery of Rs. 360 crore in the Rs. 3600-crore VVIP chopper deal with AgustaWestland.
The sources said the need to record statements of Wanchoo and Narayanan was felt as both had participated in the meeting in 2005 that allowed key changes in the technical specifications of the chopper.
They said since Narasimhan was also present in the meeting, his statement is also crucial to get additional inputs about the reasons for reducing service ceiling.
CBI has alleged reduction of the service ceiling--maximum height at which a helicopter can perform normally--allowed the UK-based firm to get into the fray as, otherwise, its helicopters were not even qualified for submission of bids.
CBI had registered a case against former IAF Chief S P Tyagi along with 13 others including his cousins and European middlemen in the case.
The allegation against the former Air Chief was that he had reduced flying ceiling of the helicopter so that AgustaWestland was included in the bids. Tyagi has refuted the allegation against him.
CBI claims the parameters regarding the height at which the helicopter can fly as well as the flight evaluation were changed in a manner that enabled AgustaWestland to clinch the deal vis-a-vis its competitor Sikorsky.