"Letter Rogatory has been issued by Metropolitan Magistrate Mumbai on Wednesday. It will enable the tax department to investigate Swiss bank accounts of Hasan Ali and his associates," a finance ministry source said.
Letter Rogatory is issued by a domestic court to its foreign counterpart to cooperate in investigation.
This will enable further probe into the Hasan Ali matter, the sources added.
After a search on the premises of Ali in 2007, income tax department had found incriminating documents containing information of $8 billion deposits in UBS AG, a Swiss Bank.
Based on the various documents, tax demand of Rs 71,846 crore (nearly $15 billion) was raised by I-T department in December 2008.
Besides Ali, persons involved in the case are his wife Rheema Hasan Ali, Hasan Ali's associate Kashinath Tapuriah and his wife Chandrika Tapuriah and a related entity R M Investment Pvt Limited.
The tax sleuths had also seized Rs 90 lakh (Rs 9 million) cash from Hasan Ali and attached three of his properties.
The Enforcement Directorate, through the Indian government, had also approached the Swiss government on the basis of these and other documents.
The Swiss Federal Tax Administration had earlier refused to share bank related information on the ground that such information regarding bank deposits of Indian residents is covered by Banking Secrecy Laws.
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