The Supreme Court (SC) of Pakistan on Thursday ordered the "immediate release" of PTI Chairman Imran Khan after terming his arrest in the Al-Qadir Trust case "unlawful", reports Pakistani media.

Chief Justice of Pakistan Umar Ata Bandial and Khan had a brief exchange of words before the order was issued. 

The Pakistan Tehreek-e-Insaf (PTI), which has been on a rampage for the past two days and whose protests have resulted in deadly clashes with police across the country, applauded the decision, while the government was unhappy with the development.

The three-member bench – headed by Chief Justice of Pakistan Umar Ata Bandial and comprising Justice Athar Minallah and Justice Muhammad Ali Mazhar – issued the verdict on PTI's petition challenging Khan's arrest.

"It is good seeing you," CJP Bandial told Khan when he was presented before the three-member bench, and also asked him to "condemn" the violent protests that took place as a result of the arrest.

Imran Khan, chairman of the Pakistan Tehreek-e-Insaf (PTI), was presented on Thursday before a three-member panel as per the Supreme Court's directive. 

The Supreme Court of Pakistan on Thursday directed authorities concerned to summon Pakistan Teheek-e-Insaf (PTI) Chairman Imran Khan before the three-member bench by 4:30pm Pakistan time today.

However, the PTI chief has been taken to court an hour later than the stipulated time.

He was brought in a convoy of 15 vehicles.

Dawn has reported that the former prime minister was taken inside the court via the judges' gate.

Chief Justice of Pakistan Umar Ata Bandial also lambasted the National Accountability Bureau (NAB) for arresting Khan from the premises of the Islamabad High Court (IHC), saying that the anti-graft agency has committed "contempt of court", reports Pakistani news outlet The News International.

A three-member Supreme Court bench – headed by Chief Justice of Pakistan Bandial and including Justice Athar Minallah and Justice Muhammad Ali Mazhar –  is hearing PTI's petition challenging the arrest of former prime minister.

"The court will issue an appropriate order today," the CJP said, adding that the court was "very serious" about the matter.

One of Imran's lawyers, Hamid Khan, appeared on the rostrum and informed the apex court that his client had approached the Islamabad High Court (IHC) for pre-arrest bail.

The lawyer said that Imran was in the process of getting his biometrics done when he was arrested, reports DAWN.

"Rangers misbehaved with Imran Khan and arrested him," Hamid said.

CJP Bandial observed that court records showed that the case had not been fixed for hearing.

The lawyer told the court that the appeal could not be filed without completing the biometric process.

Imran's political party had filed a petition in the Supreme Court a day earlier challenging the Islamabad High Court's (IHC) decision calling party chief Imran Khan's arrest by the National Accountability Bureau (NAB) "legal".

Initially, the petition was returned to the PTI after registrar's office attached objections to the plea.

The registrar's office stated that the PTI chief did not approach the relevant forum, adding that he could file an intra-court appeal, reports The News International.

It further stated that the petition did not have the signatures of the PTI chief.

But, later on Wednesday, the PTI addressed the objections of the registrar's office and it was accepted for a hearing.

Following Khan's arrest on Tuesday inside the IHC, the PTI Vice Chairman Shah Mahmood Qureshi summoned an emergency meeting of the seven-member committee to review the situation and devise a comprehensive strategy to secure the safe and early release of the party chair.

The senior PTI leader had announced the party's plan to move the apex court.