A Delhi court Monday extended interim protection from arrest to Congress leader P Chidambaram and his son Karti till May 30 in connection with the Aircel-Maxis cases. The Enforcement Directorate (ED) and the Central Bureau of Information (CBI) are probing allegations of irregularities in granting Foreign Investment Promotion Board (FIPB) approval to a foreign firm when Chidambaram was Union finance minister in 2006. The court, which had earlier granted them protection till May 6, extended this after senior advocate A M Singhvi, representing Chidambaram and Karti, filed a petition for the same. Solicitor General Tushar Mehta, appearing for the ED and CBI, had asked the court for additional time to complete the probe.