The CBI on Friday registered an FIR against the Gitanjali Group of companies based on a complaint registered by the Punjab National Bank in a multi-crore fraud case, sources said.

The PNB had filed the complaint on February 13 in the Rs 11,515 crore ($1.8 billion) fraudulent transactions.

Searches were underway on Friday at 20 locations related to the Gitanjali Group of companies in six cities and five states, the source added. Mehul Choksi, uncle of Nirav Modi, is the chairman of the Geetanjali Group

Billionaire diamond trader, Nirav Modi has been accused by the PNB of fraud along with his wife, Ami and brother Nishal Modi and partner Choksi.

On Thursday, several outlets belonging to the Modis and Choksi wre searched by the Enforcement Directorate. Assets, including gold, jewellery and diamonds had been seized.