ATTOCK, Pakistan (AP) — Pakistan’s former Prime Minister Imran Khan spent the night at a high-security prison after a court handed him a three-year jail sentence for corruption, a development that could end his future in politics.

The court ruled Saturday that Khan, who was ousted in a no-confidence vote in April 2022 but remains the country’s leading opposition figure, had concealed assets after selling state gifts.

The prison sentence could bar him from politics under a law that prohibits people with a criminal conviction from holding or running for public office. He could also lose the chairmanship of the party he founded, Pakistan Tehreek-e-Insaf, or PTI.

It's the second time this year that Khan has been detained, joining other former Pakistani prime ministers who had been arrested and seen military interventions throughout the country's political history.

But his current residence at the Attock prison is a far cry from his custodial conditions in May when he was taken to a well-appointed guesthouse on a police compound in Islamabad under a Supreme Court order. He was then allowed visitors and meetings with party colleagues.

Attock prison, in eastern Punjab province, is notorious for its harsh conditions and its inmates include convicted militants.

Authorities have further tightened security around the prison, which already has armed guards in watchtowers, by erecting barriers and blocking roads to keep people away. They have also instructed locals not to allow media onto their roofs to stop photographs and videos from leaking.

PTI lawyer Shoaib Shaheen told The Associated Press that police at the prison refused entry to a legal team who went to see Khan. He said the party will file an appeal as there are “plenty of loopholes in the verdict.”

Critics say efforts to put Khan behind bars are politically motivated and have intensified ahead of elections due to be held later this year.

They argue that Khan’s popularity and a large support base, combined with his ability to mobilize massive crowds, pose a threat to the ruling coalition and its backers in Pakistan’s powerful military that has been the final arbiter of the country’s politics since independence from Britain in 1947.

In May, Khan's arrest on corruption charges caused a wave of violent protests that swept the country. Pakistan’s Supreme Court days later ordered his release, saying his arrest was illegal.