The call comes a day after independent US media published a leaked cable confirming Khan's repeated accusations that the US engineered his ouster from power in 2022 to be true.
"We reiterate our demand that a high-powered judicial commission should be constituted to investigate the issue comprehensively and make its finding public," the party said in a statement Thursday.
The diplomatic cypher obtained by US media showed that the State Department deployed a series of incentives and threats to convince the powerful Pakistani military and its civilian allies to have Khan removed after he declared Pakistan's neutrality in the Ukrainian crisis.
A senior State Department official was revealed to have told the then-Pakistani ambassador to Washington in a March 7, 2022 meeting that "if the no-confidence vote against the Prime Minister succeeds, all will be forgiven." Otherwise, Washington warned, measures would be taken to ensure Pakistan's international isolation.
"The Cypher Story, which is now available in the public domain, has irrevocably established the credibility and justness that Imran Khan…has repeatedly reiterated regarding the development leading up to the removal of his constitutional and democratic government," PTI said.
The party called the April 10, 2022 no confidence vote "contrived" and US meddling a "blatant interference in the internal affairs of Pakistan by the country in question which was unacceptable under any circumstances."
In October 2022, Pakistan's election commission stripped Khan of his parliamentary mandate as well as the right to be elected and appointed to both the country's federal and regional legislatures for five years, after finding him guilty of selling 52 valuables stored in the Toshakhana, Pakistan's national treasury, and concealing information about gifts he received personally. In April 2022, then-opposition leader and current Prime Minister Nawaz Sharif said Khan had sold state treasures in Dubai worth a total of 140 million Pakistani rupees ($500,000). Khan has denied wrongdoing and accused his political enemies of engaging in a politicized "witch hunt" against him.
On Saturday, media reported that an Islamabad court has sentenced Imran Khan to three years in prison after finding him guilty of corrupt practices in the Toshakhana case.