On March 7, 2008, President Asif Ali Zardari of Pakistan appointed him as second Chief Justice of the Islamabad High Court, succeeding Sardar Muhammad Aslam.

On November 3, 2007, the Chief of Staff of the Pakistani Army declared a state of emergency and issued a Provisional Constitutional Order (PCO).

A 7-person panel of the Supreme Court issued an order declaring the state of emergency illegal and prohibiting all judges from taking oath on any PCO.

According to a list presented to the National Assembly of Pakistan by the Federal Government Employees Foundation through the then-Housing Minister Syed Safwanullah on April 27, 2007, Khan is one of the 61 high court judges who were allotted plots in Sector G-14 of Islamabad.

For the first time in the country's history, the Supreme Judicial Council has initiated suo motu proceedings against Khan over allegations of involvement in murky activities, including connections with the crime underworld.