A Delhi court Tuesday extended till January 11 the protection from arrest granted to former Union minister P Chidambaram and his son in the Aircel-Maxis scam. Special Judge O P Saini extended the relief granted to Chidambaram and his son Karti after the CBI and the ED submitted that new material has been recovered which needs to be collated. It also granted time till January 11 to the CBI to get sanction to prosecute some of the people accused in the case. The CBI had on November 26 told the court that the Centre had granted sanction to prosecute P Chidambaram. The case relates to alleged irregularities in grant of Foreign Investment Promotion Board (FIPB) approval in Aircel-Maxis deal. There are 18 accused in the case. Besides Chidambaram, sanction is required for the prosection of five public servants. Senior advocate Kapil Sibal, appearing for Chidambaram, had earlier requested the court to extend the protection of the former Union minister and and co-accused Karti in the both the cases filed by the CBI and the ED. The father and the son had recently denied the allegations of both the agencies that they were evasive and non-cooperative during the probe in the case. They said the allegations against them were "unsubstantiated" and there was no need of their custodial interrogation. The CBI and the ED, in their replies to the anticipatory bail pleas of Chidambarams, had alleged that they were not cooperating in investigation. P Chidambaram had filed his anticipatory bail application in May this year. His protection from arrest has been extended from time to time. The agencies have sought the custodial interrogation of both the accused, saying they have not been cooperating and, therefore, making it difficult to complete the investigation in a time-bound manner as directed by the Supreme Court. The senior Congress leader and his son have come under the scanner of investigating agencies in the Rs 3,500-crore Aircel-Maxis deal and the INX Media case involving Rs 305 crore. In its charge sheet filed earlier in the case against former telecom minister Dayanidhi Maran, his brother Kalanithi Maran and others, the CBI had alleged that P Chidambaram granted FIPB approval in March 2006 to Mauritius-based Global Communication Services Holdings Ltd, a subsidiary of Maxis. The Maran brothers and the other accused named in the CBI charge sheet were discharged by the special court, which said the agency had failed to produce any material against them to proceed with the trial. The ED is also probing a separate money-laundering case in the Aircel-Maxis matter, in which P Chidambaram and Karti have been questioned by the agency and currently their anticipatory bail is pending.