Central Bureau of Investigation (CBI) on Friday filed a fresh FIR against Gitanjali Gems and its promoter Mehul Choksi on the complaint lodged by Rs 11,300 crore fraud-hit Punjab National Bank, PTI reported. Gitanjali, Ginni, Nakshatra and Nirav Modi are the four big jewellers under the scanner, PTI reported citing a senior official. Meanwhile, India\u2019s oldest bourse Bombay Stock Exchange (BSE) has asked for clarifications from Gitanjali Gems on reports that Gitanjali, Ginni, Nakshatra are under the lens. Gitanjali Gems shares hit the lower circuit for the day, plunging by 20% to Rs 37.45 on NSE this afternoon. In the last two days alone, the shares of Gitanjali Gems have plunged by more than 35 percent. The CBI is conducting searches at 20 locations in six cities of the Gitanjali group of firms, Reuters said citing sources. On Wednesday, PNB reported that some fraudulent and unauthorised transactions to the tune of Rs 11,346 crore have taken place. The case has already been referred to the government\u2019s law enforcement agencies for recovery. Stock exchanges and Sebi are also probing Mehul Choksi and his listed company Gitanjali Gems for disclosure lapses including for postponement of a board meeting earlier this week without disclosing sufficient reasons, PTI said. A fraud of Rs 11,300 crore was detected at the Mumbai branch of the Punjab National Bank on Wednesday. The bank in a press conference held on Thursday said that it was the first one to report the fraudulent and unauthorised transactions to the government agencies on basis of which raids were conducted all across the country on the whereabouts of the culprits.