The IHC also issued notices to the Islamabad inspector general of police and the interior secretary over contempt of court.
The chief justice ordered the high court registrar to get a first information report (FIR) registered over the circumstances of the arrest, which included manhandling the lawyers present nearby as well as damage to the court building.
He also instructed the registrar to conduct an inquiry and submit a report by May 16.
Khan — who has been embroiled in dozens of cases pending since he was ousted last year — was arrested inside the premises of the high court when he appeared before the court in two cases.
His arrest follows months of political crisis and comes hours after the military rebuked the ex-international cricketer for alleging a senior officer had been involved in a plot to kill him.
PTI supporters gathered and blocked roads in cities across the country, including the capital Islamabad, Lahore, Peshawar, and Karachi, resulting in injuries to several and damage to public property.
He could be barred from holding public office if convicted, which would exclude him from elections scheduled for later this year.
Following Khan’s arrest in the afternoon, IHC CJ Farooq took notice of the matter earlier today, and summoned the Islamabad IGP and the interior secretary within “15 minutes”.
He also directed the additional attorney general to appear before the court in 15 minutes and instructed him to immediately find out who was behind the arrest.
“If an inquiry has to be conducted, action will also be taken against the prime minister and ministers,” the chief justice said.
Justice Farooq further asked: “Tell us in which case the arrest was made?”
Subsequently, the court summoned NAB DG and the anti-graft body’s prosecutor general to appear in person in 30 minutes.
When the court resumed the hearing after the break, NAB Deputy Prosecutor General Sardar Muzaffar Abbasi appeared before the court and told the court that the anti-corruption watchdog had asked the Ministry of Interior to ensure compliance with the bureau’s arrest warrant issued for Khan on May 1.
“Can arrests be made at the court premises?” the IHC CJ inquired. The prosecutor replied that any action could be taken if someone put resistance against the arrest.
The deputy prosecutor also admitted that the public property was damaged and the lawyers present with the ex-premier were manhandled.
At this, the IHC chief justice expressed displeasure saying that the appropriate method should be adopted while implementing the arrest warrant.
The NAB prosecutor told the court that Khan resisted arrest on many occasions in the past and added that he did not appear before the anti-corruption watchdog for inquiry as well.
He further termed the issuance of the PTI chief’s arrest warrants legal.
“Our primary concern is to determine whether the arrest was made legally or illegally,” the IHC CJ observed.
The NAB deputy prosecutor also maintained that there is no restriction on the arrest from the court premises, adding that in view of the court’s sanctity the ex-PM was not taken into custody from the courtroom.
During the hearing of the case, IHC Bar Association President Naveed Malik told the IHC chief justice that the court compound was attacked and lawyers were injured.
The PTI chief’s counsel Haris asked the court to inquire NAB as to when it changed the inquiry into the investigation in the Al-Qadir Trust case.
He said a copy of the investigation must be provided to Khan’s legal team if any changes are made to the inquiry of the case.
“I wrote a letter to NAB on this matter which is attached,” he said.
The council said they responded to NAB’s summon and added that the anti-corruption watchdog’s own records show malice behind the arrest.
Haris informed the court that NAB could issue arrest warrant during the investigation and added that before amendments to the National Accountability Ordinance (NAO) warrants could be issued during the inquiry,