The CBI has booked two Union Bank of India employees here for allegedly violating the RBI guidelines by depositing in the bank's chest over Rs 84 crore in old currency notes of three private firms, an official said on Tuesday.

Deputy General Manager Ashok Kumar Dhabhai and Assistant General Manager K. Shivashankar Rao were booked along with the directors of the three jewellery firms -- Pihu Gold, Satnam Jewellers and Pushpak Bullion here.

All have been booked for criminal conspiracy, cheating and forgery of Indian Penal Code, and sections of the Prevention of Corruption Act. 

The directors of the firms have been identified as Rakesh Patel, Mayur Deepak Chawla and Amit Sampat. 

Central Bureau of Investigation (CBI) spokesperson R.K. Gaur said two of the three private firms deposited Rs 47.45 crore and Rs 37.15 crore in their accounts with the Union Bank of India's branch in Zaveri Bazar during November 15-December 26 period. 

"The firms fraudulently showed the deposits by fabricating records. The amounts were further shown as transferred to the account of a third firm which has been maintaining its NPA (Non-Performing Asset) in the same branch of the bank," Gaur said. 

"The amount was later directly deposited into the currency chest of Union Bank of India in old currency notes in the guise of outright purchase (Cash Purchase) of gold from Standard Chartered Bank or other authorised bank by the third firm," he added.

Gaur said the huge cash was deposited purportedly by representatives of the private firms in an alleged conspiracy with the senior officials of the bank. 

"The accused persons violated the RBI guidelines issued on November 8, 2016," said the officer, adding the agency conducted searches at 12 places, including residential and office premises of accused persons, and recovered incriminating documents.