A senior ED official told IANS: "We have attached four Swiss bank accounts with a balance of Rs 283.16 crore."

The official said that Letters Rogatory (LR) had been sent to the authorities of foreign jurisdictions to enforce the attachment orders.

The ED action comes months after it filed a supplementary chargesheet against Nirav Modi's wife Ami Modi, a US national, for being the beneficiary of alleged purchase of two apartments at Central Park in New York using $30 million of laundered money which her husband obtained fraudulently from PNB through Letters of Undertaking and Foreign Letters of Credit.

The chargesheet was filed on February 28. It is alleged that the amount was routed through Ami's HSBC Bank accounts.

The attached apartments are part of Nirav Modi's Rs 637 crore worth of foreign properties the ED seized in October last year.

According to agency officials, the apartments were purchased in the name of The Ithaca Trust. One of the properties in Central Park South, New York, was in the name of Central Park Real Estate LLC, a Firestar Group company. In 2018, it was transferred to the Trust.

The alleged beneficiary of The Ithaca Trust is Ami Modi and her children and the settler of the said trust was Nirav Modi's sister Purvi Modi, a Belgian national.

The agency had also attached a flat worth Rs 56.97 crore on Marylebone Road in London.

According to the ED official, the property was bought in the name of the Belvedere Holdings Group Ltd which was managed by Trident Trust in Singapore and established by Monte Cristo Trust. The official said the said trust has Purvi Modi as settler and beneficiary.

Nirav Modi and his uncle Mehul Choksi are under probe by both the CBI and ED. Nirav Modi is currently lodged in a London jail while Choksi is now in Antigua.