Chief Justice Ather Minallah of the Islamabad High Court late Saturday ordered the probe in response to a petition from the daughter of former minister Shireen Mazari.
Minallah questioned the decision by officials in Islamabad to allow police from a Punjab provincial district to make the arrest in the capital.
Mazari, who served in the Cabinet-level position under former Prime Minister Imran Khan, had been detained by police near her Islamabad home earlier in the day.
Fawad Chaudhry, former information minister in Khan’s administration, alleged that Mazari — the senior leader in Khan’s Pakistan Tehreek-e-Insaf party — had been politically targeted by the new administration of Prime Minister Shahbaz Sharif under the guise of a land dispute dating back to 1972.
Hours after Mazari’s arrest, Chief Minister of Punjab province Hamza Shahbaz ordered her release and late Saturday she was brought to the Islamabad court for an urgent hearing. She was then released.
Mazari has been critical of Sharif’s government on Twitter since Khan’s government was toppled in a no-confidence vote in Parliament last month. Khan’s party lawmakers resigned from the body’s lower house in protest and Khan is mobilizing supporters through public rallies across the country to pressure the government into an early election.