After giving him treatment, he was put to intense grilling about money trail and identification of documents in the multi-crore rupee deal, they said.
He was allowed to sleep for two hours between 4 am and 6 am Wednesday before being provided with breakfast.
After 6 am, he was again subjected to questioning session by the officials of the Special Investigation Team of the CBI, they said.
Escorted by a small convoy of police cars and bikes, he was taken to the CBI headquarters' lockup at the ground floor of the imposing 11-floor steel and glass building where he reached around 1.20 AM on Wednesday.
He was taken to the Patiala House court around 4 PM Wednesday which sent him to five days CBI custody.
The CBI wants to question him to confront him with certain documents and confidential material which he allegedly had sent to his masters in Italy through fax, the agency claimed.
It also wants to know how the money, Euro 42.27 million, which was received by Michel's companies from Finmeccanica and AgustaWestland, was distributed further to establish money trail of alleged bribes paid to swing the Rs 3,600 crore 12-helicopter deal for VVIP flights, it said.
The agency has alleged that Michel has evaded any probe in the matter which puts him on a different pedestal than Guido Haschke -- another middleman -- who faced trial in Italy and entered in plea bargain.
The CBI had filed a charge sheet 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's spokesperson said.
Michel was behind bars in Dubai since he was arrested and sent to custody pending the legal and judicial procedure in the UAE.
It was alleged that he 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 m to 4,500 m.
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.
On January 1, 2014, India scrapped the contract with Italy-based Finmeccanica's British subsidiary AgustaWestland for supplying 12 AW-101 VVIP choppers to the IAF over alleged breach of contractual obligations and charges of paying kickbacks to the tune of Rs 423 crore by it for securing the deal.
Michel is one of the three middlemen being probed in the case, besides Haschke and Carlo Gerosa.
The CBI has alleged there was an estimated loss of Euro 398.21 million (approximately Rs 2,666 crore) to the exchequer in the deal that was signed on February 8, 2010 for the supply of VVIP choppers worth Euro 556.262 million.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)