A massive manhunt has been underway to nab the perpetrators ever since Prime Minister on November 8 announced that Rs 500 and Rs 1000 currency notes cease to be legal tender.
Here are 10 cases of major banks that had their officials booked for indulging in alleged illegal conversion or exchange of demonetised currency notes.
Kotak Mahindra Bank, Delhi
The Enforcement Directorate on December 28 arrested a Kotak Mahindra Bank manager for converting Rs 35 crore demonetised currency into new notes, and having alleged links with hawala trader Paras Mal Lodha and Delhi-based lawyer Rohit Tandon.
A city court later sent him to seven-day ED custody.
The ED officials arrested branch manager Ashish Kumar and booked him under the provisions of the Prevention of Money Laundering Act.
The ED officials informed the court that Ashish as a manager at Kotak Mahindra Bank's Connaught Place branch had indulged in criminal conspiracy with various persons.
Axis Bank, Noida
Income Tax officials on December 15 raided an Axis Bank branch in Noida and froze 20 suspect accounts with deposits totalling around Rs 60 crore, police said.
A police officer said the suspect accounts at the Axis Bank branch in Sector 51 in Noida were opened in the name of several fake companies and a few low income individuals.
The officer said these accounts came to the I-T Department's notice when a Noida jeweller sold gold worth Rs 600 crore after the November 8 demonetisation and deposited the money at the Noida bank branch.
Tax officials seized several documents from the branch for scrutiny.
Meanwhile, Axis Bank said in a statement that it had started rigorous compliance procedures and applied all its analytic capability to identify accounts with suspicious activity since the November 8 demonetisation.
Axis Bank, Chandni Chowk
On December 9, tax officials seized over Rs 100 crore from 44 suspect accounts from an Axis Bank branch in the Chandni Chowk area in Delhi.
Income Tax officials raided an Axis Bank branch in the national capital and identified at least 44 fake bank accounts.
According to reports, the accounts did not follow KYC norms and old notes worth Rs 100 crore were deposited in them.
According to reports, a total of Rs 450 crore had been deposited in the branch since November 8, the day when Prime Minister Narendra Modi had announced the demonetisation of Rs 500 and Rs 1000 notes.
HDFC Bank, Gurugram
The Gurugram Police on December 11 registered a case against a HDFC bank cashier in DLF Phase-2, in connection with the November 30 seizure of old currency notes worth Rs 10.96 lakh. The case has been registered against the bank cashier named Suakant, a businessman Sunny Khanduja and two of his helpers in civil line Police station here.
Four of the accused have been charged under Section 420, 311 and120B of Indian Penal Code (IPC).
As per reports, the bank manager was involved in converting old scrapped currency of higher value to new one for which he was getting ransom amount.
HDFC Bank, Mohali
Four employees, including a branch manager, of HDFC bank, were sacked in Chandigarh for allegedly indulging in unauthorised exchange of demonetised currency notes, the bank said in a statement on December 3.
"Services of the employees, posted with the Sector-15 branch here, were terminated immediately after it was discovered they were allegedly favouring a person known to one of them by exchanging his demonetised currency notes with new notes," it said.
The bank said "an isolated" incident of "unauthorised" currency exchange involving the employees came to its notice after its systems detected an inconsistency.
In another incident, a bank manager and a cashier of a public sector bank were arrested by the Punjab police yesterday in Bathinda for allegedly charging money to "replace" demonetised currency notes.
Vaidyanath Cooperative Bank, Mumbai
It was found out that the bank was involved in the conversion of black money owned by doctors into white.
Officials of Vaidyanath Cooperative Bank , started by prominent BJP leader, Gopinath Munde came under the Income Tax lens after Mumbai Police had seized Rs 10.10 crore from a car in Tilak Nagar area on December 15.
CBI on December 23 conducted raids at 11 premises of Vaidyanath Urban Cooperative Bank in Maharashtra in connection with recovery of Rs 10 crore demonetised notes.
After the revelation of deposits of black money in the bank, Pritam Munde, BJP MP and sister of Maharashtra minister Pankaja Munde, and the director of the bank had claimed that the money was not black money and was only being taken from one branch of the bank to another.
The Mumbai District Central Co-operative Bank
Allegedly, a sum total of Rs 5000 crore in old currency notes was deposited in the bank post demonetisation.
The sum was deposited in different branches of the bank.
Investigations are underway.
RBI, Bengaluru
CBI arrested two employees of cash department of Reserve Bank of India in Bengaluru on December 17 in connection with alleged conversion of Rs 1.99 crore of demonetised currency with specified bank notes of Rs 2,000 and Rs 100.
CBI sources said Senior Special Assistant Sadananda Naika and Special Assistant A K Kavin were arrested for unauthorised exchange of the currency and have been booked under charges of criminal conspiracy and cheating besides provisions of Prevention of Corruption Act.
CBI spokeperson Devpreet Singh said in furtherance with the criminal conspiracy, the accused, along with other unknown officials, who were entrusted with the responsibility of new currency notes, "fraudulently" gave away new notes to the tune of Rs 1.99 crore to RBI officials and others.
It is alleged that the exchange was done in violation of exchange limits imposed by the Bankers' Bank.
RBI, Mysore
CBI had earlier arrested another employee of RBI in a separate case in which currency worth over Rs six lakh was converted by him using his influence over officials of State Bank of Mysore.
RBI official K Michael was arrested in connection with seizure of Rs 5.70 crore in new currency notes.
HDFC Bank, Haryana
Haryana Police on December 26 said it has solved the case of loot of Rs 5 lakh from near village Sinhpura in Kurukshetra district and arrested four persons, including an Assistant Manager of a private bank who happened to be the alleged gang leader.
They committed the alleged crime when currency notes were being taken from one branch of the private bank to another, police said.
Ravinder Kumar had lodged a complaint that on December 22 the bank money was looted from him and security guard Paramjit Singh after throwing chilly powder in their eyes on Jhansa road near village Sinhupara.
A case was registered against three unidentified persons on the basis of this complaint.
However, on interrogation, Ravinder Kumar revealed that he himself had planned to loot the bank money to pay his debt of Rs 40,000 to Avtar Singh.
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