Retired police officer O P Mathur, who had headed the probe into the Sohrabuddin fake encounter case as chief of Gujarat Central Investigation Department, appeared before the CBI for questioning on Thursday.
Mathur, who is now in-charge of Gujarat government's Rasksha Shakti University, is being questioned at the Central Bureau of Investigation office in Gandhinagar after he was summoned by the agency on July 27.
He had, however, failed to appear then due to personal reasons.
Mathur was the head of state CID, which investigated the encounter of Sohrabuddin and alleged murder of his wife Kausarbi in November 2005, before the probe was transfered to the CBI by the Supreme Court in January this year.
CBI sources said they would be able to get valuable inputs from Mathur in connection with the case.
He was earlier summoned by the CBI in May but his statement was not recorded at that time.
The central probe agency has already recorded the statement of another retired IPS officer G C Raigar, who also headed the state CID when it was probing the fake encounter case. He was called in as a witness.
The CBI has also summoned former investigation officer in the case Geetha Johri, who has been asked to appear before the agency by August 10.
The central agency has arrested former Gujarat home minister Amit Shah on charges of criminal conspiracy, murder, kidnapping and extortion on July 25.
After taking over the case, the CBI has also arrested IPS officer Abhay Chudasama, a key conspirator in the case.
It has also recorded statements of Rajneesh Rai, who had arrested three IPS officers -- D G Vanzara, Rajkumar Pandian and Dinesh M N -- considered to be main conspirators behind the encounter.
IPS officer G L Singhal, presently with the Gujarat ATS has also being questioned. Singhal was Gandinagar superintendent of police when the encounter took place.The earlier probe by the CID had lead to the arrest of 14 policemen including Vanzara and Pandian of Gujarat cadre and Dinesh of Rajasthan cadre for staging a fake encounter of Sohrabuddin.