The Directorate of Revenue Intelligence has initiated proceedings against billionaire jeweller Nirav Modi in a 2014-’15 duty evasion case, reports said.

Modi and his firms are accused of causing customs losses by not correctly declaring the value and amount of polished and cut diamonds that were being imported, the Hindustan Times reported. He also allegedly illegally diverted these imported stones to local markets, overvalued exports and violated rules of Special Economic Zones.

An unidentified revenue officer told the Hindustan Times that the Directorate of Revenue Intelligence has permission to prosecute Modi and three of his firms under the guidelines of the Central Board of Excise and Customs. “He will be prosecuted under relevant sections of the Customs Act, 1962, and the Indian Penal Code for false declaration and evasion of duty,” the officer said.

Meanwhile, the Central Bureau of Investigation on Sunday arrested four people allegedly connected to the Rs 12,703-crore fraud involving Modi and the Punjab National Bank, Mint reported.

Two of them were former employees of the Nirav Modi Group of Companies – former Assistant General Manager Manish K Bosamiya and former Finance Manager of Firestar International Ltd Miten Anil Pandya – a CBI spokesperson told Mint.

They were arrested for allegedly applying for the Letters of Undertaking from the Punjab National Bank, the report said.

The third was Sanjay Rambhia, an auditor for the Nirav Modi Group. The agency also arrested Aniyath Shiv Raman Nair, a former director of Gili India Ltd, which is part of the Gitanjali Group owned by Modi’s uncle Mehul Choksi.

The CBI spokesperson said Nair was the authorised signatory on applications asking the Punjab National Bank for the Letters of Undertaking and Foreign Letters of Credit.