Supreme Court (SC) on Wednesday ordered Attorney General of Pakistan Ashtar Ausaf to form a judicial commission to probe the murder of social worker Perween Rahman.

The case was being heard by a two-member SC bench headed by Justice Gulzar Ahmed and including Justice Azmat Saeed.

During the hearing, the court lashed out at Sindh police for its negligence in the case's investigation, accusing officials of "covering up" their failure in solving the murder of the social worker. The court also ordered Advocate General of Sindh Barrister Zamir Ghumro to appear in court and provide details of the investigations.

Read: Perveen Rahman's murder — the great cover-up

Police officials present in court today told the bench that five suspects had been arrested, out of which one had confessed to being involved in Rahman's murder. The claim did not sit well with Justice Ahmed who questioned Sindh police's capability of holding an independent investigation instead of relying on a mere confession.

"The person who has admitted [to the crime] in jail will withdraw his confession in trial court," Justice Saeed remarked. "The police officials don't try to reach the depth of the matter."

"Where should we send Sindh's police officers to make them learn how to conduct a proper investigation?" Justice Ahmed asked. He noted that the murder took place in 2013 and the killer has still not been arrested.

Raheel Kamran, senior counsel of Rahman's sister Aquila Ismail, also alleged that the police officials that were involved in the investigation had mishandled the case, leading Justice Ahmed to wonder if the police were trying to "cover up" their failure.

The police officials admitted that the case had been mishandled and told the court that the department was taking action against the officers that were responsible. Justice Saeed demanded how the police could botch up a high-profile case and said that the officers involved in the original investigation must be asked whose orders they were acting upon.

The hearing of the case was adjourned for two weeks.

Related: In memory of my sister, Perween Rahman

Rahman, a media-shy social worker and director of the Orangi Pilot Project, that worked for the development of the impoverished neighbourhoods across the country, was gunned down in cold blood near her office in Malir, Karachi, in 2013.

The very next day, police killed a Taliban operative named Qari Bilal in an encounter and claimed he was the murderer, resulting in a closure of the case.

The Supreme Court of Pakistan in April 2014 had ordered authorities to conduct a fresh probe into her murder after a judicial inquiry had revealed that police officers had manipulated the investigation.

During a hearing in 2014, the SC was also told that the slain philanthropist was in possession of a map detailing the lands that have been illegally occupied by affiliates and associates of various political parties that operated in Karachi.