The CBI on Thursday conducted searches at the premises of former finance secretary Arvind Mayaram after filing an FIR against him and a UK-based company for alleged corruption in the supply of exclusive colour shift security thread for Indian bank notes, officials said. The CBI, in its FIR, alleged that Mayaram, the UK-based company De La Rue International Ltd and unidentified officials of the finance ministry and RBI hatched a criminal conspiracy to extend undue favour to the firm.

The agency alleged that Mayaram as finance secretary granted an "illegal" three years extension to an "expired contract" with the company for supplying exclusive colour shift security thread without taking any mandatory security clearance from home ministry or informing the then finance minister, they said.

The extension granted by Mayaram was allegedly the fourth, the FIR said.

The CBI registered the FIR under IPC sections related to criminal conspiracy and cheating and provisions of the Prevention of Corruption Act. It was followed by searches at Jaipur and Delhi residence of the 1978-batch retired IAS officer, days after he had joined the Bharat Jodo Yatra of Congress leader Rahul Gandhi.

The agency had registered a preliminary enquiry in 2018 on a complaint from the Chief Vigilance Officer of the Department of Economic Affairs in the Ministry of Finance.

(With inputs from agencies)