Imran Khan with his wife Bushra Bibi, signs documents to submit surety bond over his bails in different cases at an office of the Lahore High Court. File

The latest charges follow a string of convictions against Imran in the months leading up to the Feb.8 national election, where his supporters won the most seats overall.

Imran Khan, 71, has been in jail since August in connection with other cases, and has previously denied the allegations.

He had already been convicted in four cases with sentences of as much as 14 years in prison — including two on graft charges, that also disqualified him from taking part in politics for 10 years. His trials are being held on a jail's premises on security grounds.

The couple pleaded not guilty to the indictment charges, Imran Khan's Pakistan Tehrik-e-Insaf (PTI) party said.

The latest indictment is related to Al Qadir Trust, which is a non-governmental welfare organisation set up by Imran Khan and his third wife Bushra Bibi in 2018 when he was still in office.

Prosecutors say the trust was a front for Imran Khan to receive a valuable 60 acres (24 hectares) of land in a district outside Islamabad and another large piece of land close to Khan's hilltop mansion in the capital as a bribe from a real estate developer, Malik Riaz Hussain, who is one of Pakistan's richest and most powerful businessmen.

Hussain, who hasn't appeared before an anti-graft agency to submit his reply to summons issued to him late last year, has denied any wrongdoing. The PTI condemned the indictment.

"Trials conducted behind prison walls (are) only meant to pave the way for miscarriage of justice," it said in a statement, terming them politically motivated cases to keep Khan behind bars.

The PTI party has rejected the election results, alleging widespread fraud.