LAHORE, Aug 5 (Reuters) - Police arrested Pakistan's former prime minister Imran Khan in the eastern city of Lahore on Saturday, his lawyer said, after a court sentenced him to three years in prison for illegally selling state gifts.

Legal experts say guilty verdict reached by a district court could end Khan's chances of participating in national elections that have to be held before early November.

"Police have arrested Imran Khan from his residence," Khan's lawyer Intezar Panjotha told Reuters. "We are filing a petition against the decision in high court."

Khan's political party, Pakistan Tehreek-e-Insaf (PTI) said in a statement they had already filed another appeal to the Supreme Court earlier on Saturday.

Khan's arrest and detention for several days in May over a seperate case had sparked intense political turmoil and deadly clashes had erupted between Khan supporters and police.

Pakistani media and a Reuters witness described police surrounding Khan's residence in Lahore on Saturday after verdict was released.

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 has denied any wrongdoing.

The 70-year-old cricketer-turned-politician was 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 ($635,000).