ISLAMABAD - The Federal Investigation Agency (FIA) on Thursday once again summoned PTI Chairman Imran Khan into the audio leak inquiry related to the US cipher. An FIA officer reached Khan’s residence at Zaman Park in Lahore with the summons asking the former prime minister to appear before the probe team on December 6 in Islamabad. On the directions of the interior ministry, the premier investigation agency had launched an investigation into the audio leak purportedly featuring Khan, PTI leaders, and a senior bureaucrat while discussing the cipher issue. In at least two audio clips that surfaced in September, ex-premier Khan, his principal secretary Azam Khan, former federal minister Asad Umar and ex-foreign minister Shah Mahmood Qureshi could be heard discussing how to build a narrative and “play” with the cipher to give an impression that PTI was being ousted from power through a “foreign conspiracy”. Last month, FIA had issued notices to Khan and Shah Mahmood Qureshi to appear before it on November 7 and November 3 respectively, but the PTI chief could not make it due to his injuries as a result of assassination attempt on him.