The prison block in which Julian Assange is being detained under extradition proceedings has been locked down following an outbreak of coronavirus. Three prisoners are understood to have tested positive for Covid-19 in House Block 1 at Belmarsh prison in south-east London, prompting prison and public health officials to place the building under increased restrictions. The number of coronavirus cases within the prison estate increased significantly last month, with positive results returned at 45 jails across England and Wales, including 10 prisons that have never reported outbreaks. Assange’s public relations agency issued a release confirming the prison governor at Belmarsh had written to inmates in House Block 1 to inform them of the outbreak. The letter states that all prisoners and staff are to be swabbed to detect Covid-19 at the prison with results revealed in 24 to 48 hours. Within the block, all exercise has been stopped, showers prohibited and meals are to be provided direct to the prisoner’s cell, the agency said. A Prison Service spokesperson said: “We’ve introduced further safety measures following a number of positive cases.” Assange, 49, was jailed in April last year for absconding bail. He was later told he would not be released at the end of the custody period and would remain in jail while he awaits separate extradition proceedings to the US, where he is wanted on an 18-count indictment. All but one are for violations of the country’s Espionage Act. Assange’s partner, Stella Moris, the mother of their two children, said: “I am extremely worried about Julian. Julian’s doctors say that he is vulnerable to the effects of the virus. But it’s not just Covid. “Every day that passes is a serious risk to Julian. Belmarsh is an extremely dangerous environment where murders and suicides are commonplace. Julian is one of the most widely recognised press freedom and government accountability advocates alive. UK decision-makers must change course before they cause Julian to lose his life.” Prisons were placed under a highly restrictive regime during spring, which was slowly but not completely relaxed across the summer and autumn. Social visits had been reintroduced to all jails in England and Wales and were not suspended again until November as the second national lockdown was imposed. At the end of October, 1,529 prisoners had tested positive for Covid-19 since March, an increase of 883 on the September figure, Ministry of Justice (MoJ) figures show. The MoJ has been testing all symptomatic prisoners since April. A mass testing programme of all inmates in 28 prisons – covering about a fifth of the population – has been running since July.