Islamabad/Karachi: Pakistan’s former Prime Minister Nawaz Sharif failed to appear on Monday before an anti-graft tribunal where he was to be indicted on corruption charges along with several family members and co-defendants in the case.

Meanwhile, authorities arrested Sharif’s son-in-law, also a co-defendant in the case. The son-in-law, Mohammad Safdar was taken into custody at the Islamabad airport after he and his wife, Maryam Nawaz, arrived from London, said Cabinet minister Talal Chaudhry.

Amid tight security, police later brought Safdar before the anti-graft tribunal, called Accountability Court, where he appeared alongside his wife.

The corruption charges against Sharif, his two sons, daughter and son-in-law stem from an investigation into documents leaked from a Panama law firm that showed the Sharifs had undisclosed assets abroad.

Chaudhry, the Cabinet minister, told reporters that Safdar and his wife had returned to Pakistan “to appear before the court as they believe in the rule of law.”

Sharif is currently in London with his wife Kulsoom Nawaz, who is said to be recovering from throat cancer surgery.

The Sharifs have denied any wrongdoing and have labelled the corruption proceedings against them as politically motivated.

Two of Nawaz’s sons are also due to appear before the NAB court, along with Finance Minister Ishaq Dar.

Nawaz was disqualified by the Supreme Court in July for not declaring a source of income that he disputes receiving.

Pakistan’s top court also ordered a wide-ranging NAB investigation and trial into Sharif family members.

The Supreme Court specified that the trial be concluded within six months by NAB, which has in the past been derided as toothless because rich and powerful politicians were seldom convicted.

Safdar, who was arrested soon after midnight, was expected to be released after his NAB court appearance with Maryam this morning.

Television footage showed some supporters from the ruling Pakistan Muslim League-Nawaz (PML-N) trying to stop the car from leaving the airport, including some who lay down in front of it.

A senior PML-N official urged them to give way.

Khawaja Saad Rafique, a minister in the PML-N Cabinet, said on Twitter no resistance was made to Safdar’s arrest, even though the party had “serious reservations” about the judicial process.

Sharif’s disqualification stems from the Panama Papers leaks in 2016 that appeared to show that his daughter and two sons owned offshore holding companies registered in the British Virgin Islands and used them to buy properties in London.

The Supreme Court initially declined to dismiss Nawaz but ordered an investigation into his family’s wealth. After the probe it disqualified him and ordered a NAB investigation and trial into the family.

Some senior PML-N officials, including Maryam, have hinted that elements of Pakistan’s powerful military had a hidden hand in the Supreme Court disqualification that forced Nawaz to resign. The army denied playing a role.

The case against the Sharifs has gripped Pakistan, with analysts expecting the negative newsflow from the hearings to hurt PML-N in the run-up to the next general elections, likely in mid-2018.

The Supreme Court disqualified Sharif from office in July, forcing him to step down over corruption allegations and undisclosed assets. Sharif has denied any wrongdoing. He and some of his party leaders have claimed there are “hidden hands” behind his dismissal and spate of corruption cases.

Last week, Sharif appeared before the anti-corruption court but the tribunal had to delay his indictment after his children, who are co-defendants in the case, failed to appear before Judge Mohammad Bashir.

Sharif’s lawyer Khawaja Haris on Monday requested that the judge exempt Sharif from appearing. The judge reserved his decision on the request but granted Sharif’s daughter and her husband bail. He also adjourned the case till October 13.

Sharif’s ruling party expressed anger over Safdar’s arrest.

Sharif’s two sons, who also skipped out on Monday’s hearing, are also said to be in London with their ailing mother.

The case against the former prime minister has become the centre of much domestic media attention in Pakistan.

Last week, Pakistan’s National Assembly — where Sharif’s party holds majority seats — adopted a bill passed earlier by the Senate regarding election reforms which paves the way for Sharif to regain his position as president of the ruling party Pakistan Muslim League.