Former Pakistan Prime Minister Imran Khan has been jailed for three years for illegally selling state gifts he received while premier.

Legal experts say a conviction in the case could end Khan's chances of participating in national elections that have to be held before early November.

'Judge Humayun Dilawar announced that involvement in corrupt practices has been proven,' Pakistan TV said.

Khan was not present for the hearing at the Islamabad High Court, and the judge ordered his immediate arrest. It's the second time the popular opposition leader has been detained this year. 

The 70-year-old cricketer-turned-politician was arrested at his home after police descended on his residence in Lahore - Pakistan's second biggest city. He will now be taken to the capital, Islamabad.

'I have just received the information that Imran Khan has been arrested,' Attaullah Tarar, Special Assistant to Prime Minister Shehbaz Sharif, told reporters. 

Khan is facing over 150 cases brought against him since being ousted in April last year - charges he says are politically motivated. Khan's legal team said they would be filing an immediate appeal.

It's important to mention there was no chance given to present witnesses, neither was time allotted to round up arguments,' a member of the team said.

The sentence relates to an inquiry conducted by the election commission, which found Khan guilty of unlawfully selling state gifts during his tenure as prime minister from 2018 to 2022. 

Khan - who was ousted after a no-confidence vote in parliament in April 2022 - denies any wrongdoing.

The former Pakistan PM is accused of misusing his premiership to buy and sell gifts in state possession that were received during visits abroad and worth more than 140 million Pakistani rupees.

His dramatic arrest in May - where he was filmed being forcibly removed from court by security officers - sparked nationwide violent demonstrations from supporters of his Pakistan Tehreek-e-Insaf (PTI) party in almost all of the country's major cities. 

Hundreds of protesters were arrested after government and military property was attacked and at least eight people died as unrest gripped Pakistan. In the aftermath of his release following three days in custody, PTI has been targeted by a crackdown with thousands of arrests, reports of intimidation and muzzling of the press.