Air Marshal Gujral (retd) arrived at the CBI headquarters in New Delhi in the morning and appeared before the investigation team probing the case.
He was one of the many senior officials who were part of the meeting in 2005 when a decision to alter the required specifications was taken.
The agency has called former IAF chief S P Tyagi on Monday.
Both have been questioned at length in 2013 but the fresh round of questioning was necessitated after the April 7 order of an Italian court.
The CBI has so far maintained that Gujral was questioned as a witness, but remained tightlipped if he will still retain the same status.
The agency, so far, has not levelled any allegation against him.
The agency had registered a case against former IAF chief Tyagi along with 13 others including his cousins and European middlemen in the case.
Tyagi has denied the allegations.
The allegation against the former air chief was that he had reduced flying ceiling of the helicopter from altitude ceiling requirement from 6,000 m to 4,500 m (15,000ft) so that AgustaWestland was included in the bids.
However, this decision was taken allegedly in consultation with the officials of Special Protection Group and the Prime Minister’s Office, including then National Security Advisor M K Narayanan.
The CBI has alleged reduction of the service ceiling -- maximum height at which a helicopter can perform normally -- allowed the United Kingdom-based firm to get into the fray, otherwise, its helicopters were not even qualified for submission of bids.
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