New Delhi, May 11: CBI has questioned UPSC chairman Subir Datta as part of its probe into the alleged irregularities in the Rs 1,150 crore Barak missile deal with Israel.

While the CBI was officially tight-lipped about the questioning, sources in the agency said Datta, who was a former Defence Secretary, was questioned to ascertain "certain facts" before CBI quizzed George Fernandes who was the Defence Minister when the deal was signed in October 2000.

They said Datta was asked by the CBI about the note that was put before the Cabinet Committee on Security by Fernandes about the need for procurement of Barak missiles from Israel in which opposition by a section of scientists was not mentioned.

Datta, a 1967 batch IAS officer of West Bengal cadre, who joined Union Public Service Commission in July 2003, had also been examined by the CBI in the coffin scam earlier.

The sources said that Datta had served in the defence ministry during the period when purchases were finalised. He served as additional secretary from 1998 to 2000 and later as secretary, defence production and supplies (2000-02) before being appointed as Defence Secretary (2002-03).

His questioning was done to enable the CBI to understand the role of bureaucracy, the sources said.

After examining him, the CBI will question Fernandes, who is an accused in the case, and Jaya Jaitley, former president of Samata Party. The CBI has already questioned former Navy Chief Admiral Sushil Kumar in connection with the alleged irregularities.

CBI claimed in its FIR that the contract price for purchasing seven Barak missile was about USD 17 million which was higher than the price offered by Israel in early 1996.

"Fernandes wanted the proposal to be initiated from below and he eventually overruled the learned opinion of then scientific advisor to Raksha Mantri (Defence Minister) in order to favour Israel aircraft industries and others," the CBI alleged.

Former President A P J Abdul Kalam, who was then scientific advisor, had "strongly opposed" the proposal made in 1999 by Admiral Kumar to import two surface-to-air missiles but Fernandes "overruled" this view and gave the go-ahead, it charged.

"The then raksha mantri (Fernandes) overruled opinion of then scientific advisor to Defence Minister... Against import of any missile system and gave a go-ahead to the proposal of Sushil Kumar on June 28, 1999," the CBI alleged.

The defence ministry had put up a note for CCS which returned the proposal of acquiring some precision-guided missiles as it had decided to defer them so that they could be considered by the next government.

"Despite this note by the Defence Secretary, Fernandes wrote back on September 3, 1999, that installation of Barak ...Ystems on ins fleet was absolutely essential and therefore, the CCS might be apprised of the urgency of requirement and to seek its approval," the FIR said.

The case came to light in 2001 when a sting operation was carried out by the news portal Tehelka that exposed alleged irregularities in several defence deals, including the one to purchase the Barak systems.