Concern is growing over press freedom following the arrest of a photographer after he took and shared photos of a protest at a former military barracks controversially housing asylum seekers. Andy Aitchison, 46, documented a demonstration outside Napier barracks in Folkestone, Kent, on Thursday morning as protesters threw buckets of fake blood at the doors of the site amid allegations of overcrowding, poor hygiene, significant risks posed by Covid-19, and limited access to healthcare and legal advice. Aitchison spent several minutes covering the brief protest, during which signs were held saying: “Close Napier now” and: “There will be blood on your hands” after at least 120 men at the barracks tested positive for Covid this month. Five police officers arrived at Aitchison’s nearby home six hours later and arrested him on suspicion of criminal damage, in front of his children. In an interview with the Guardian, he said: “I really feel like they’re trying to clamp down on the freedom of the press. The government is cracking down on people who are saying things they don’t want them to say, and that’s not right.” Aitchison’s photos were used in a number of press reports, as well as the Guardian’s photographs of the day. The freelancer who shoots for Getty and regularly has his pictures published by national media, was taken to a police station and remained in a cell for almost seven hours after having his fingerprints and DNA taken. Officers gave him a detective thriller as well as golf, fishing and motorbike magazines to keep him occupied. He said he had told the police in his interview: “I’m a photographer. This is what I do for work. These pictures have already been published and I will be paid for them.” Remarking on the seemingly bizarre nature of the situation, he added: “From the start I just thought, what’s going on? I was there for work and haven’t committed criminal damage.” Pamela Morton, the National Union of Journalists national freelance organiser, said the union was “extremely concerned” at Aitchison’s arrest. “Andrew was present solely as a journalist and took no part in the protest,” she told the Independent, which first reported the news. “News gatherers are key workers and it is their role and duty to report on matters of public interest. The police should not be seeking to interfere, prevent or restrict what journalists record in this way.” Ian Murray, executive director of the Society of Editors, told the Guardian: “This is very concerning. We are constantly told journalists, including press photographers, are an essential part of our democratic system in this country and a free media is to be protected. “But words are not enough. It is actions that count and arresting press photographers is not something that should be happening in a liberal democracy.” The protest came before a fire at the former military barracks on Friday, which the home secretary, Priti Patel, suggested was set deliberately. Kent police have launched an arson investigation. Under the terms of Aitchison’s bail, he is not allowed to go near Napier barracks. He said he was frustrated at not being able to document the fire and events afterwards but respected the conditions to avoid further arrest. “It feels like if you’re photographing someone doing something wrong, rather than doing something about it they’ve tried to shut it down,” he said. Kent police said they were called following a report of a protest in Shorncliffe, Folkestone, at around 8am on 28 January. “Officers attended and a 36-year-old man from the Dover area was arrested on suspicion of causing criminal damage,” a spokesperson said. “Further inquiries led to the arrest of a second man, aged 46, in Folkestone at around 3pm the same day. Both men have been released on bail until 22 February.” The force said the blaze caused a significant amount of damage to at least one part of the site, where hundreds of asylum seekers have been living. Five men have been arrested following the fire. A 31-year-old was arrested on suspicion of assaulting a security guard on Friday evening, the force said. A further four men were arrested in connection with the incident the following morning. Patel said on Friday: “The damage and destruction at Napier barracks is not only appalling but deeply offensive to the taxpayers of this country who are providing this accommodation while asylum claims are being processed. “This type of action will not be tolerated and the Home Office will support the police to take robust action against those vandalising property, threatening staff and putting lives at risk.”