Sources said ED is looking into financial details and bank accounts of the company and its promoters.
No summons or notices have been sent as of now to the company or its promoters, they said.
The Noida-based phone-makers have also come under the scanner of the I-T Department which is looking into its financial structure and has obtained documents, including those from the Registrar of Companies (RoC), in this regard.
The Ministry has sought a clarification from Ringing Bells for marketing its 'Freedom 251' mobile phone without a BIS (Bureau of Indian Standards) certification and also asked Uttar Pradesh government to check the firm's credentials.
The company said it has received around 6 crore registrations for the phone.