A Delhi court on Monday issued a notice to former Union minister P Chidambaram’s son Karti Chidambaram based on the Enforcement Directorate’s petition to revoke the interim relief from arrest granted to both of them, PTI reported.

The investigating agency said it needed to conduct custodial interrogation in connection with the Aircel-Maxis money laundering case. Special Central Bureau of Investigation Court Judge OP Saini asked Karti Chidambaram to reply by September 18.

The case pertains to clearances that the Foreign Investment Promotion Board granted to the firm M/S Global Communication Holding Services Ltd for investment in Aircel in 2006. Chidambaram was the finance minister at the time and his son Karti Chidambaram allegedly facilitated bribes in the Aircel-Maxis transaction. The investigative agency is also looking into why P Chidambaram approved the investment when only the Cabinet Committee on Economic Affairs can give the green signal.

On August 7, a Delhi court extended the interim relief from jail granted to Karti Chidambaram and his father in the case till October 8. The order was related to cases filed by the Central Bureau of Investigation and the Enforcement Directorate alleging corruption and money laundering respectively.

On July 31, the court granted the Central Bureau of Investigation time till October 1 to obtain sanctions from authorities to prosecute some of the accused in the case. The agency had filed a new chargesheet on July 19 against 18 people, including the former minister and his son. The chargesheet also named retired and serving government officials.

The Enforcement Directorate is also investigating another money-laundering case in the Aircel-Maxis matter and had filed a chargesheet against Karti Chidambaram on July 13.

Both Karti Chidambaram and P Chidambaram have denied allegations in the matter.