Speaking out on behalf of her ex-husband Imran Khan, Jemima Goldsmith has denounced the "serious and concerning developments" in Pakistan's treatment of the imprisoned former prime minister and demanded his immediate release.

The film producer, who was married to Mr Khan from 1995 to 2004 and has two sons with him who are both British citizens, raised concerns about Mr Khan’s treatment in prison, accusing the Shehbaz Sharif government of cutting his access to lawyers and family visitations and even severing electricity to his cell.

Mr Khan has been held at the Adilala Jail in Rawalpindi in northern Pakistan since 2023, after a court handed him a three-year jail sentence in a corruption case. He faces some 150 charges in total, all of which his party says are politically motivated.

Ms Goldsmith raised her concerns in a series of X posts late on Tuesday, in which she expressed her hesitancy to speak out. “For the past few years, I’ve been bullied & harassed into silence by PML-N (Pakistan’s ruling party) goons, including rape threats & countless conspiracy theories,” she wrote.

Ms Goldsmith said that in addition to cutting off in-person visits in defiance of a court order, prison authorities have prevented Mr Khan from making weekly calls to his two sons, Sulaiman and Kasim, who live in London.

She said 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.

“He is now completely isolated, in solitary confinement, literally in the dark, with no contact with the outside world," she said, adding that his lawyers were concerned about his safety and well-being.

Ms Goldsmith’s comments echo concerns raised by Mr Khan’s Pakistan Tehreek-e-Insaf (PTI) party in recent days.

She leveled the allegations against the Pakistan government at a time when Islamabad is hosting an ongoing two-day SCO summit, which saw the rare participation of Indian foreign minister Subrahmanyam Jaishankar.

Pakistan police have arrested dozens of Mr Khan's supporters and members of his PTI party who attempted to march in the capital demanding his release.

Ms Goldsmith also accused the Pakistan government of detaining members of Mr Khan's family in an "attempt to silence them and all political opposition".

Mr Khan's nephew, Hassan Niazi, has been in military custody since August 2023, while the cricketer's sisters Uzma and Aleema Khan were being held in prison for speaking out for their brother.

"I disagree with Imran Khan on many political issues. But this is not about politics – it’s about my children’s father, his human rights and international law," Ms Goldsmith said.

"I owe it to my children to try to create some awareness about what is happening in Pakistan," she added.

A UN human rights panel in July called for Mr Khan’s immediate release saying he has been detained “arbitrarily in violation of international laws”.

The Working Group on Arbitrary Detention said the legal cases brought against the former prime minister were part of a “much larger campaign of repression” against him and his party.

Mr Khan was banned from seeking political office and his party was barred from contesting the national election earlier this year. He has since applied from prison to become the next chancellor of Britain’s Oxford University.

Pakistan’s government has denied allegations that Mr Khan is being arbitrarily detained and has said it wants to ban his PTI party altogether, accusing him of leading his supporters to engage in violent unrest targeting facilities linked to the military establishment. It has also accused him of foreign collusion and “treason” over his decision to dissolve parliament in the final days of his government in 2022. He was eventually ousted from power in a vote of no confidence.