The CBI has taken over investigation into alleged swindling of USD 171 million (about Rs 1,200 crore) from the Union Bank of India by hackers in 2016, officials said Monday. The case, which was being probed by the Mumbai Police, pertains to transfer of about Rs 1,200 crore from the Nostro account of the bank to various countries on July 20, 2016, they said. During a reconciliation exercise of the Society for Worldwide Interbank Financial Telecommunication (SWIFT) messages, the bank had found that USD 171 million was unaccounted for, they said. The money was reportedly traced to banks in Cambodia, Thailand, Taiwan and Australia from the nostro account of the bank, they said. A nostro account refers to an account that a bank holds in a foreign currency in another bank overseas to enable foreign trade by its clients. The transfer was done from two banks based in New York which managed Union Bank of India's nostro accounts. The funds were reportedly recovered through diplomatic manoeuvres, they said. The bank in its complaint on July 21, 2016 to the Mumbai Police had pegged the amount to be USD 30.01 million (Rs 201 crore) but the police which had registered an FIR on August 25, 2016 mentioned the amount to be USD 171 million which was about Rs 1,200 crore by the then exchange rates. "We find that somebody might have unauthorisedly accessed our computer system, extracted data and ultimately misused to cheat the bank by fraudulently and dishonestly using the unique identification features," the initial complaint from the bank on July 21, 2016 said. It is reportedly suspected that the money was transferred through a hacking attempt using a malware attached in the mail which was opened by a bank employee, they said.