CBI today started examination of suspects in connection with alleged kickbacks received in the Rs 3600 crore VVIP chopper deal as it reached Chandigarh and questioned executives of IDS Infotech and Aeromatrix--firms named in its preliminary enquiry (PE).

CBI sources, without revealing identities said officials of both the firms were examined in connection with PE registered by it.

The agency suspects that a portion of Rs 362 crore bribe was allegedly routed to Indian nationals, through Tunisia and Mauritius, camouflaged as payments for engineering contracts to Chandigarh-based--IDS Infotech and Aeromatrix.

Both the companies had denied involvement in the bribery scandal.

The sources said records related to ownership of these companies, the contracts handled by them and several other related documents were also collected from these officials by the CBI investigators.

They said executives of the two Chandigarh-based firms were asked to join the probe of the agency into allegations that several million Euros were paid to three European middlemen to swing the VVIP helicopter deal in favour of Finmeccanica's subsidiary AgustaWestland.

Two middlemen, from their share of commission, allegedly paid huge sums of money to several Indian nationals under the cover of payments of engineering contracts with the two Chandigarh-based firms, the PE said.

The agency had registered a preliminary enquiry against 11 people including former IAF chief S P Tyagi, his three cousins, European middlemen and four companies--Finmeccanica, AgustaWestland, IDS Infotech and Aeromatrix. All these suspects have refuted allegations against them.

Tyagi's three cousins--Julie, Dosca and Sanjeev-- suspected European middlemen Carlo Garosa, Christian Michel and Guido Haschkhe, advocate Gautam Khaitan formerly associated with Aeromatrix and its CEO Praveen Bakshi, former Finmeccanica Chairman Giuseppe Orsi, former AgustaWestland CEO Bruno Spagnolini, have also been named in the CBI enquiry.

The CBI will also examine other accused including former IAF Chief S P Tyagi and his cousins this month in connection with the PE, the sources said.

The agency team which visited Italy last month has got some documents from Finmeccanica on the basis of which it has started probe in the matter.

The Italian prosecutor in its investigation report has claimed that Haschkhe and Gerosa, through the Tyagi brothers, managed to change the tender details, modifying the 'operational ceiling' from 18,000 feet to 15,000 feet altitude, thus allowing AgustaWestland to take part in the tender.

The report also claimed that the duo managed to introduce a comparative flight trial with non-functional engine, thus facilitating AgustaWestland helicopters, the only ones which had three engines, swinging the deal in its favour.

The CEOs of the two Italian companies, arrested by local authorities, had also "paid Guido Ralph Hashcke and Carlo Gerosa, through a consultancy contract between AW spa and Gordian Services Sarl an amount of 400,000 Euros (about Rs 2.8 crore)of which 100,000 Euros (Rs 72 lakh) were paid cash to the Tyagi brothers (Julie, Docsa and Sandeep", the report claimed.

The report suggests that the middlemen had close contacts with the family of former IAF Chief Air Chief marshal S P Tyagi, particularly his three cousins.