ISLAMABAD (Reuters) - Pakistani opposition leader Imran Khan said on Wednesday (Nov 2) that he expected a Supreme Court corruption investigation to topple Prime Minister Nawaz Sharif and repeated his calls for Mr Sharif to resign immediately.

The court on Tuesday (Nov 1) agreed to Mr Khan's request to set up a judicial commission to probe his corruption allegations against Mr Sharif, stemming from revelations that his children owned offshore companies in the tax haven of the British Virgin Islands.

Mr Khan then backed down on his threat to paralyse Islamabad by bringing in a million protesters, defusing tensions after days of clashes between his supporters and the police.

Instead he decided to hold a "celebratory" rally on the edge of the capital, where he accused Mr Sharif and his younger brother Shahbaz, the chief minister of Punjab province, of being responsible for the clashes between police and supporters of his Pakistan Tehreek-e-Insaf (PTI) party.

The Supreme Court is due to hold its first substantive hearing on the matter on Thursday.

Mr Sharif's ruling party has said it will participate in an investigation into Panama Papers revelations but rejected an opposition demand that it should focus principally on Mr Sharif's family.

Mr Khan's challenge stems from documents leaked from the Panama-based Mossack Fonseca law firm that appeared to show that Mr Sharif's daughter and two sons owned offshore holding companies registered in the British Virgin Islands.

Mr Sharif's family denies wrongdoing, and there was no mention of Mr Sharif himself owning any offshore companies.

Holding offshore companies is not illegal in Pakistan, but Mr Khan has implied that the money and London apartments held by the companies, amounting to millions of dollars, were gained by corrupt means.