The Central Bureau of Investigation (CBI) on Monday questioned four top employees of Nirav Modi’s company and 13 serving and retired employees in the Rs 11, 400 crore Punjab National Bank (PNB) scam.

The CBI also arrested three more PNB officials — Becchu Tiwari (Chief Manager, Forex Dept), Yashwant Joshi (Scale II Manager, Forex Dept) and Praful Sawant (Scale I, Export). The agency also conducted searches at PNB’s Mumbai-based Brady House branch, where the fraud took place, for the second consecutive day and also sealed it.

On the other hand, the Enforcement Directorate official conducted searches at over 39 locations, including Nirav’s flat in the Samudra Mahal apartments in Worli and said assets worth as much as Rs 5,716 crore has been seized so far.

While the CBI is scrutinising the details of Letters of Undertaking and Letters of Credit submitted by the PNB, the bank’s head office too has scrutinised its LoUs and submitted a report to the CBI.

The CBI questioned Vipul Ambani, Vice President finance, Ravi Gupta, Chief Financial officer, Saurabh Sharma, President, International Finance and Subhash Parab, DGM Finance of Firestar Diamond International Pvt. Ltd to unravel the entire fraud that took place with the help of PNB employees.

Earlier, the Central Vigilance Commission (CVC) asked the PNB and Finance Ministry officials to submit a report on how the Rs 11,400-crore scam took place despite several monetary regulations in place. The CVC has given the bank 10 days to present the report. Earlier in the day, senior PNB and Finance Ministry officials had a meeting with the CVC in connection with the fraud case. The officials gave a two-hour long presentation to the vigilance body. The CVC also had a meeting with CBI officials during which the commission was told that it was a system failure at multiple levels. The commission exercises superintendency over the CBI in corruption-related matters.

The investigating agency continued to conduct raids for the fifth consecutive days at several of showrooms of Gitajali Gems.

The Income Tax Department also attached seven properties of Mehul Choksi and Gitanjali group in Mumbai. While four of these attached assets were in the name of Gitanjali Gems Limited, two were in the name of Mehul and one in the name of Gili India Limited.

The CBI examined 12 PNB officials to find out about the irregularities in fraudulent issuance of LoUs and FLCs in favour of companies of Nirav and his uncle Mehul. On the other hand, the ED has conducted searches at over 40 more locations in several cities across India. The agency raided 10 places in Mumbai, six each in Ahmedabad and Bengaluru, four in Chennai, three in Surat, two each in Bihar, Lucknow, Jalandhar and Hyderabad and one in Delhi.

Following the unravelling of the PNB fraud, two senior officials of Gitanjali Gems -- Chandrakant Karkare and Pankhuri Warange -- resigned from the company, according to a regulatory filing with the stock exchanges on Monday. The names of the two officials were mentioned in the FIR filed by the CBI on the fraud.

Sources in the CBI said that Vipul Ambani had been holding the position VP , Finance, for over three years and is believed to have been aware of the financial transactions carried out by the company of the jeweller-businessman.

According to CBI, the Gokulnath Shetty has told investigators that he had unauthorisedly obtained Level-5 password to the SWIFT system to authorise issuance of money through Letters of Undertaking (LoUs) and Foreign Letters of Credit (FLCs). Shetty made the startling revelations when sleuths of CBI questioned him about the modus operandi of providing guarantee to other banks under the LoUs and issuance of enhanced FLCs.

Shetty also informed the investigators that he shared the password with other individuals, essentially employees, as well as directors of Nirav’s company. The Level-5 password was the key allowing him to reach out to several banks to release the money to the Nirav and Gitanjali groups through the SWIFT system, which, according to PNB amounted to a fraud of Rs 11,300 crore.

Over two dozen firms and 18 businessmen who had taken franchise of Nirav and Mehul’s jewellery brand between 2013 and 2017 also reportedly found themselves at the receiving end of frauds committed by the duo -- with the cases involving amounts up to Rs 200 million (Rs 20 crore).

They have also conducted searches at 38 other locations in several cities, including Mumbai, Pune, Aurangabad, Thane, Kolkata, Delhi, Jammu, Lucknow, Bengaluru and Surat. It seized fresh assets worth Rs 22 crore that include precious stones, cash and gold from the premises of Nirav, his relative and business partner Mehul and others. On the summons to Nirav, officials said there has been no response on the summons sent to Nirav or the other accused so far. "We will find out how the money laundering took place. As it is in foreign jurisdiction it will take time to investigate," the ED officials said.