New Delhi: Christian Michel James, the alleged middleman in politically-sensitive Rs 3,600-crore AgustaWestland chopper deal, was brought to India late on Tuesday night following his extradition by the UAE, the CBI said.

He was questioned by the central investigating agency through the night.

Michel will be produced in court on Wednesday.

Here are key highlights to this big story:

• Michel, 57, landed at the Indira Gandhi International (IGI) Airport on a Gulfstream jet at 2235 hours, official sources to news agency PTI said. He was arrested in the UAE last year on the basis of an Interpol notice and was out on a bail.
• The operation code-named 'Unicorn' was carried out under the guidance of National Security Advisor Ajit Doval and being coordinated by interim CBI Director M Nageswar Rao, the CBI spokesperson said.
• A team of the agency's officers led by Joint Director Sai Manohar was in Dubai to bring him back, it said.
• The agency said that Michel has been brought back to India after completion of the extradition process. The UAE government had cleared the extradition of Michel after his appeal against the move was turned down by a court there.
• Michel's alleged involvement in the chopper deal surfaced in 2012 as a middleman for swinging the deal in favour of AgustaWestland and for making illegal payment of commissions or kickbacks to the Indian authorities, CBI spokesperson Abhishek Dayal said. Michel was wanted for investigation but he escaped and had avoided joining the probe, he said.
• A charge sheet was filed against him in September last year. "An open non-bailable arrest warrant dated September 24, 2015, was issued by the special judge, CBI cases, Patiala House Courts, New Delhi," CBI spokesperson said. On the basis of this warrant, a Red Corner Notice was issued by the Interpol which led to his arrest in Dubai in February 2017, he said.

• The ruling BJP said the extradition in the case from the UPA era is a diplomatic victory for India and could spell "serious trouble" for the Congress's "first family", referring to Gandhis. It also asserted that the development was an unequivocal affirmation of the Narendra Modi government's "seriousness in fighting corruption".
• It was alleged that Michel had entered into a criminal conspiracy with co-accused persons, which included the then IAF chief SP Tyagi and his family members, and the public servants had abused their official positions by reducing service ceiling of the VVIPs helicopter from 6,000 metres to 4,500 metres.
• The reduction in ceiling made AgustaWestland eligible for contract worth 556.262 million Euros, which was awarded to it by the Defence Ministry on February 08, 2010, for procurement of 12 VVIP helicopters.
• He has been alleged to be a "historical consultant" of the AgustaWestland helicopters in the UK with technical operational knowledge of the aircraft, the military bases and the pilots, the CBI spokesperson said in a statement.
• Michel was allegedly a frequent visitor to India and was operating as a middleman for defence procurement through a wide network of sources cultivated in the IAF and the Defence Ministry at different levels, including through retired and serving IAF officials, CBI said.
• Michel allegedly shared the information collected from the IAF and the ministry with his associates, who used to transmit the despatches through fax to other counterparts sitting in Italy and Switzerland, the central investigating agency said. "...He was updating and informing the management of Finmeccanica and AgustaWestland, namely Giuseppe Orsi and Bruno Spagnolini and others, about his efforts in India for securing supply contract of VVIP Helicopters," the CBI statement said.