In yet another development signalling the mounting worries for senior Congress leader and former Union minister P Chidambaram, the Enforcement Directorate on Monday summoned him in a money-laundering probe in the alleged aviation scandal during the UPA era. As per officials, Chidambaram has been asked to appear before the probe officials on August 23 at the agency office in order to record his statement. The case is related to losses that Air India suffered because of an alleged multi-crore aviation scam and irregularities in fixing air slots for international flights. Previously, ex-aviation minister Praful Patel was also questioned by the agency on granting permission for air traffic rights to foreign airlines and also purchase of as many as 111 aircraft for Air India when he was the minister. It is believed that the ED now plans to question former finance minister on their leads in the case. Patel had appeared before the ED close to two months back in connection with a probe into alleged money-laundering in the case. In its charge sheet, the agency has named aviation lobbyist Deepak Talwar, alleging that the latter was in regular touch with then aviation minister. He was arrested by the ED earlier this year. he allegedly finalised a number of communications that were addressed to Patel on behalf of foreign aviation companies, purportedly helping them with undue favours. The latest development for Chidambaram comes amid his ongoing trouble in the INX Media case and the Aircel Maxis case. Earlier this month, both Chidambaram and his son Karti were granted provisional relief from being arrest till August 23. The case is related to alleged irregularities grating Foreign Investment Promotion Board (FIPB) clearance in the Aircel-Maxis agreement.