The income-tax department has asked the Rs 3,000-crore Yash Birla Group for an explanation regarding five undisclosed foreign bank accounts, according to documents accessed by ET. The accounts hold more than Rs 300 crore. The I-T department embarked on a six-month investigation based on a lead from the financial intelligence unit of the finance ministry.

In January, the department conducted search and seizure operations at group companies in more than 15 locations in Mumbai and Delhi. One account is in Switzerland, while the other four are in Singapore. The HSBC bank account in Switzerland was opened by the late Ashok Birla, father of Yash Birla, prior to his death in 1990.

Besides, the group is alleged to have three bank accounts with Barclays, one of which showed a balance of about $50 million (Rs 300 crore). The fourth Singapore account is with Credit Suisse. The Yash Birla Group didn't respond to detailed queries sent by ET.

"Except the balance in one bank account, cash in other bank accounts is not known as the company officials are not cooperating with the investigations," said a senior IT official requesting anonymity as he's not authorised to speak to the media. The department suspects these accounts to have more than Rs 600 crore, he added.

While two of these accounts are maintained in the name of Mokopane Trust formed in 2010-11, one is in the name of Confiance in Singapore. The other two accounts are maintained in the name of Yashovardhan Birla, reveals the IT investigations. IT sources said the trusts operate the bank account on the instructions of Yash Birla. The I-T department has initiated proceedings to attach assets of group companies in Singapore.

The department has also written to the concerned authorities in Switzerland, Singapore and other countries through its foreign tax and tax research division seeking details of the accounts. However, the department fears that the money in the Singapore accounts has already been moved elsewhere.