Pakistan's former prime minister, Nawaz Sharif, failed to appear before a tribunal on Monday, 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.

The son-in-law, Mohammad Safdar, was taken into custody at Islamabad airport after he and his wife, Maryam Nawaz, arrived from London, said cabinet minister Talal Chaudhry.

Amid tight security, police later took Safdar to the anti-corruption 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 which showed that the Sharifs had undisclosed assets abroad.

Minister Mr Chaudhry 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 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, requested on Monday 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 until October 13.

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

Sharif's two sons, who also missed 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.