New Delhi: The Central Bureau of Investigation (CBI) has asked five countries to identify companies and bank accounts owned by former Union Minister P. Chidambaram and his son Karti Chidambaram, an official said on Friday.

A senior CBI source related to the probe told IANS that "letters rogatory have been sent to five countries - United Kingdom, Switzerland, Bermuda, Mauritius and Singapore - seeking details of shell companies allegedly floated by Chidambaram and his son and their connected bank account details."

The agency's action comes two days after it arrested Chidambaram in connection with alleged irregularities in the Foreign Investment Promotion Board approval in 2007 to the INX Media for receiving overseas funds of Rs 305 crore during his tenure as Finance Minister.

The Enforcement Directorate later registered a case of money laundering on the basis of the CBI's FIR. The source said that the agency suspects that father-son duo held several immovable properties and over 16 bank accounts in these countries.

The source also said that the Enforcement Directorate probe has highlighted how the persons connected with the shell companies have executed a will in favour of Chidambaram's granddaughter.

Chidambaram was arrested on Wednesday night from his residence in Delhi's upscale Jor Bagh area after high drama, while CBI officials scaling the six-foot-high boundary to enter his residence.

A Delhi court on Thursday sent Chidambaram to CBI custody till Monday.