Just checked it out myself
“Settled in the province of Punjab, Khan’s family descended from the Pashtun, Niazi Shermankhel tribe of Mianwali.” But father or mother the point is he has roots in that region..
http://en.wikipedia.org/wiki/Imran_Khan
Iskander Mirza was no angel, besides he wrote his own obituary by appointing Gen. Ayub Khan as CMLA.