RAWALPINDI: On March 9, the National Accountability Bureau (NAB) summoned Imran Khan, the chairman of the Pakistan Tehreek-e-Insaf (PTI), his wife Bushra Bibi, Shah Mehmood Qureshi, Fawad Chaudhry, and Pervez Khattak. Several hours after NAB Chairman Aftab Sultan submitted his resignation after allegedly refusing to “toe the line,” the Rawalpindi branch of the anti-corruption watchdog called the PTI leader. “The competent authority has taken cognizance of an offence allegedly committed by the accused persons under the provisions of NAO, 1999,” the anti-corruption activists stated in their notice to Khan. Following the resignation of NAB Chairman Aftab Sultan, the former premier, his wife, and top PTI officials have been asked to testify before the investigators.