Chitalia was produced before a special CBI court here in the afternoon after he was detained at the airport and questioned by the agency. Judge S R Tamboli remanded him in CBI custody till March 17.
The Central Bureau of Investigation said that Chitalia had left the country in the last week of January, as did the prime accused Mehul Choksi and Nirav Modi.
"There was a look-out notice against him, hence the immigration officials detained him at the airport as soon as he arrived from Bangkok," an agency official said.
Special prosecutor A Limosin told the court that Chitalia reported directly to Choksi.
"Chitalia was instrumental in preparing applications for putting through the fraudulent transactions of the LoUs (Letters of Undertaking) and FLCs (Foreign Letters of Credit) with the active connivance of key accused Gokulnath Shetty," Limosin told the court.
Shetty is a retired deputy manager of Punjab National
Chitalia was also the authorised signatory of Choksi's Gitanjali Group for issuance of applications for LoUs and FLCs, he said.
"He is the mastermind for putting through fraudulent transactions along with Choksi. He was also privy to the modalities for putting through the transactions," the agency said in the remand plea.
Meanwhile, the court today also remanded Shetty, earlier arrested in connection with the case of Modi's firms, in CBI custody till March 15 in connection with the case of Choksi-owned firms.
The Rs 12,636-crore fraud was allegedly perpetrated by Modi and his uncle Choksi, the promoter of Gitanjali Gems.
It is alleged that they got LoUs and FLCs of Rs 12,636 crore issued in favour of foreign branches of Indian banks based on fraudulent claims.
The accused PNB officials allegedly did not enter the instructions for these LoUs in their internal software to avoid scrutiny. They were sent through an international messaging system for banking called SWIFT, used to pass instructions among banks globally to transfer funds.
An LoU is a guarantee which is given by an issuing bank to Indian banks having branches abroad to grant short-term credit to the applicant. In case of default, the bank issuing the LoU has to pay the liability to the credit-giving bank.