A British-Iranian political prisoner being held in Tehran on spying charges has sent a recorded message saying that the jail he is in was in chaos because of coronavirus and appealing for the UK government to do more to help secure his temporary release.

Anoosheh Ashoori was transferred three days ago within Evin prison to ward four, one of the wards he claims housed coronavirus victims previously. Ashoori was sentenced two years ago to 10 years in jail on charges of spying for Israel, a charge he vehemently denies.

Iran is releasing a large number of prisoners, including some political prisoners, on bail, but has refused to release most of those with sentences longer than five years. Some older prisoners with longer sentences have been released.

In the recording, from a phone call to his wife, Sherry, in London, he said people were arriving in the new ward from quarantine.

In a call from the prison recorded by his family, Ashoori said “As we entered [the new prison ward] the soldiers were wearing worn-out masks, and no gloves. Nobody checked anybody for high temperature. All our stuff they touched when we entered”.

He added: “Last night bedbugs were biting everyone. Nobody slept through the night. Today we have newcomers who are murderers and all different outlaws. Someone was sent from corona[virus] quarantine.

“It is chaos and I cannot explain how bad this situation is. All the places are filthy with bedbugs. I cannot explain how bad this situation is. It needs international attention.” He added that he did not know why, as he saw it, human rights groups were keeping silent.

The reasons for the transfer within the ward to what are regarded as far less sanitary conditions have not been explained to the political or security prisoners, but more than 50,000 prisoners are being released nationwide temporarily amid fears that the virus could rapidly spread within prisons.

At least six prominent journalists and activists have been temporarily released in recent days.

Iran’s health ministry said in the past 24 hours 1,075 new cases of coronavirus infections, and 75 more deaths, had been recorded. Both numbers are records for a single day. The total number of cases has risen to 10,075 and the death toll to 429. A total of 3,276 people have also recovered from the disease, while the government estimates the peak may be about a week away.

Iran insists conditions in jails are clean, necessary tests are being done and it has responded to the crisis through its release programme.

A list of 10 political prisoners who were due to be released on furlough was read out to the male political prisoners last week including two dual nationals, one from the US and one from the UK. Their identities have not been divulged.

Ashoori’s son Aryan said he was prepared to camp outside No 10 and the Foreign Office to press ministers to do more to help his father.

Sherry said: “This is playing with people’s lives. This is abandoning people. My husband is 65 years old, and he has done absolutely nothing wrong. Iran seems to be mocking the Europeans.”

Iran does not recognise the status of dual nationals, and so will not receive UK representations.

Richard Ratcliffe, the husband of another imprisoned British-Iranian, Nazanin Zaghari-Ratcliffe, is still hoping his wife will be temporarily released. She had reportedly fallen ill, but the prison authorities have said she has recovered.

Human Rights Watch, in a release on Wednesday, said it had received reports that prisoners had tested positive for coronavirus, including in Evin prison and others in the cities of Euromieh and Rasht.

On 27 February, in an open letter, families of 25 prisoners detained for their activism pleaded with judicial officials to fully release or at least grant temporary release to their loved ones.

On 2 March, Jared Genser, an American lawyer who represents the family of Siamak Namazi, an Iranian-American businessman sentenced to 10 years in prison, said in a statement: “A prisoner in Siamak’s ward, who slept just several cells down the same hallway, had acute respiratory symptoms, [and] tested positive for coronavirus.”