British dual nationals should not be used as “political leverage” by Iran, according to a UK minister, who pushed back on claims in Tehran that a multimillion pound debt is to be settled for Nazanin Zaghari-Ratcliffe’s release. The renewed focus on the plight of the 42-year-old British-Iranian woman – who has been held in Iran since 2016 – continued amid some signs that Iran could be on the verge of releasing two US-Iranian nationals. James Cleverly, whose ministerial brief covers the Middle East and north Africa, said on Monday that the “arbitrary” detention of British dual nationals including Zaghari-Ratcliffe should remain separate from ongoing legal disputes with Iran. “We have also seen a number of occasions where the Iranian regime have used disinformation. We’re hearing inaccurate reports coming out over the last couple of days,” he said, after an Iranian state TV report said that Britain would pay a £400m debt to secure her release. “On the one hand, they are saying that these proceedings are legitimate, we don’t agree with that at all, but then also saying that they are linked to this legal dispute – it can’t be both,” he told Sky News. Meanwhile, it has emerged that two high-profile Iranian-American dual nationals detained in Tehran may have been moved to a different location inside their prison in a procedure that has previously led to the release of detainees. The moves, according to sources inside Tehran’s Evin prison, had taken place despite fresh outright denials by both the Iranian foreign ministry and the US that a prisoner swap is imminent. Iranian sources on Sunday claimed a swap had been agreed for four prisoners, and that the UK had agreed to pay an outstanding £400m debt to Iran. Sources inside the prison said that two American-Iranians, Morad Tahbaz and Siamak Namazi, were moved to a special debriefing part of the prison. Tahbaz was moved on Saturday and Namazi on Sunday to a different bloc that had previously been used to brief prisoners that are being released, and to extract commitments. Two other former prominent detainees, Xiyue Wang and Nizar Zakka, were moved in the same way prior to their earlier release. Britain’s foreign secretary, Dominc Raab, moved closer on Sunday to accepting that Zaghari-Ratcliffe was being held state hostage by the Iranians when he said it was difficult to argue with that characterisation. Raab, who said Iran’s treatment of her amounted to torture, also for the first time said her fate was now tied to not only a £400m debt that the UK government owes to Iran but also the outcome of talks in Vienna on the future of the 2015 Iran nuclear deal. Zaghari-Ratcliffe’s husband, Richard Ratcliffe, said the family had “heard nothing” about a deal to secure her release, as hopes were raised by the suggestion that the long-running dispute had been resolved. Cleverly told Times Radio that ongoing legal disputes with Iran should be kept separate from the “arbitrary” detention of British nationals by Iranian authorities. “The British dual nationals, and Nazanin is one of them, held in arbitrary detention by Iran should be released.”