Imran Khan's ex-wife Jemima Goldsmith concerned about his welfare

The ex-wife of Pakistan's former prime minister Imran Khan has called for his immediate release, citing "serious and concerning" reports about his treatment in prison.

Jemima Goldsmith said on Tuesday the Pakistani authorities had stopped all visits to him by his family and lawyers, postponed court hearings, and prevented him calling his two sons since early September.

There was no statement from Pakistani authorities on her statement.

Electricity had been cut to his cell and he was no longer allowed out at any time, while the jail cook had been sent on leave, she wrote in a lengthy post on social media platform X.

"He is now completely isolated, in solitary confinement, literally in the dark, with no contact with the outside world," Goldsmith, who was married to the former Pakistan cricket team captain from 1995 to 2004.

The couple have two sons, Sulaiman and Kasim, who live in London.

A panel of UN experts in July criticised Pakistan for arbitrarily detaining Khan in breach of international law to apparently prevent him for running for political office.

Pakistan government had rejected the UN report, saying Khan's detention is an "internal matter" of the country.

Khan, 72, was prime minister of Pakistan from 2018 to 2022, and has been embroiled in more than 200 legal cases since he was ousted in a parliamentary no-confidence vote.

He has been detained since August last year and barred from standing for office. He has since applied to become the next chancellor of Britain's Oxford University.

Goldsmith said Khan's family had also been targeted, and his sisters and nephew arrested and jailed unlawfully, while she also claimed that she had faced rape and death threats from her ex-husband's political opponents.

The release of Khan, his nephew and sisters, plus the re-establishment of contact with his sons will provide "assurance first-hand that he is well and not being mistreated", she added.

"I disagree with IK on many political issues," she wrote. "But this is not about politics –– it's about my children's father, his human rights & international law."

Pakistan's government has denied that Khan's rights are being abused.

Khan "is entitled to all rights under the national Constitution and laws, as well as international principles," Pakistan's Law Minister Azam Nazeer Tarar had said in July.