ISLAMABAD (Reuters) - Police arrested Pakistani 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 a conviction in the case could end Khan's chances of participating in national elections that have to be held before early November.

Khan's political party, Pakistan Tehreek-e-Insaf (PTI) said in a statement they had already filed an appeal in the country's Supreme Court over the district court case.

Local media and a Reuters witness described police surrounding Khan's residence in Lahore after the 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).

(Reporting by Charlotte Greenfield; Editing by William Mallard)