Rishi Sunak has joined police chiefs in calling for press freedom after it emerged journalists have been arrested and held in custody during Just Stop Oil protests.

Charlotte Lynch, of LBC, told of her “terrifying” five hours in a police cell, a day after documentary maker Rich Felgate and photographer Tom Bowles were arrested for reporting on the activists on the M25 in Hertfordshire.

Mr Sunak said it is “vital” that journalists are able to do their job freely, “without restriction”, as the chief constable of Hertfordshire Police called for a review into the arrests.

Mr Sunak said it is “vital” that journalists are able to do their job freely, “without restriction”, as the chief constable of Hertfordshire Police called for a review into the arrests.

The Prime Minister’s official spokesman told reporters: “I am cautious about commenting on specific incidents. Operational decisions are a matter for the police but the Prime Minister strongly believes in championing press freedoms.

“We wouldn’t want to see those freedoms impeded while journalists are going about their day-to-day business”.

Ms Lynch had been reporting on the activists from a road bridge over junction 21 of the M25 on Tuesday for around 45 minutes when she was approached and questioned by two officers.

After showing them a press card and having explained she was reporting on the demonstration, the officers handcuffed her, took her phone and arrested her on conspiracy to commit a public nuisance.

They wanted to know how Ms Lynch knew about the protest, she said.

There’s an enormous amount of pressure in play around those protest issues for the reasons that you would understand

Ms Lynch said: “It was absolutely terrifying being in a cell with a pad for a bed in one corner and a metal toilet in the other.

“I was just doing my job. What’s also terrifying is what this means for press freedom. It was blindingly obvious I was a reporter.”

Documentary maker Rich Felgate and photographer Tom Bowles had been capturing the activists on a footbridge over the M25 near Kings Langley, at close to 11am on Monday when they were handcuffed.

The pair, both of whom say they have no affiliation with the group, had their equipment seized and were taken to a police station, despite efforts to show their press cards.

Mr Bowles, 47, from Hackney, east London, told the PA news agency he was held until 1.30am, hours after his wife and 14-year-old daughter were woken up as three officers searched their home.

The protests are a source of legitimate public interest and journalists, filmmakers and photographers have a right to attend protests and report on behalf of the public

Speaking to journalists at a conference in Westminster on Wednesday, the chairman of the National Police Chiefs’ Council, Martin Hewitt, said officers are under pressure when dealing with protesters but media should not be prevented from reporting on them.

He said: “There’s an enormous amount of pressure in play around those protest issues for the reasons that you would understand.

“But, of course, there is a right for journalists to go and report on those occasions and that shouldn’t be prevented in any way.”

Metropolitan Police Commissioner Sir Mark Rowley said: “Press freedom is really important and you will often want to be – and quite rightly be – quite close to where difficult things are happening so you can report it well and I absolutely, absolutely support that.

“The principle that you’re going to be close to the action sometimes and we should be sensitive to press freedom, of course I completely agree with.”

Home Secretary Suella Braverman later said the reports she had heard were “concerning”, but added: “I think we should allow any investigation into what’s happened to run its course and I wouldn’t want to pre-judge any finding.

“I don’t exactly know what has happened with certainty. I wouldn’t want to comment. All I know is reports and speculation, if I’m honest, so I haven’t read into it or been updated fully on the details.”

It came after Liberal Democrat MP Daisy Cooper asked the Commons deputy speaker Nigel Evans how the House could summon Ms Braverman to explain and apologise for the treatment of journalists covering protests given the “severity of the incidents”.

Ms Cooper, the MP for St Albans, added: “We are not an authoritarian state. The ability of journalists to do their job unhindered is a vital part of our democracy.”

Hertfordshire Police said officers had been “using their professional judgment” to clear possible protesters from the roads.

A statement from the force read: “Chief Constable Charlie Hall recognises the concerns over the recent arrests of journalists who arrived at these locations and have been present with the protesters at the scenes.

“Additional measures are now in place to ensure that legitimate media are able to do their job.

“In addition, Mr Hall is today requesting an independent force to examine our approach to these arrests and to identify any learning we should take in managing these challenging situations.”

Dawn Alford, executive director of the Society of Editors, said: “The Society is deeply concerned by reports this week of a number of journalists being arrested while reporting on protests by the campaign group Just Stop Oil.

“The protests are a source of legitimate public interest and journalists, filmmakers and photographers have a right to attend protests and report on behalf of the public.

“We strongly condemn the arrest of journalists in the course of their work and will be writing to Hertfordshire Police to seek an urgent explanation and seek assurances that its officers respect the rights of journalists and understand that such actions threaten press freedom.”

Former shadow attorney general Baroness Shami Chakrabarti told LBC: “If the police are now going to start arresting journalists for conspiracy to commit a public nuisance – in other words for knowing that a demonstration is about to take place – then they are effectively shutting down the free press, the free media, in this country.

“And that means the public don’t get the opportunity to judge for themselves whether the police have policed a particular demonstration well or badly, or indeed whether the protesters behaved well or badly.

“So this is very, very serious.”

Education Secretary Gillian Keegan also said: “Journalists shouldn’t get arrested for doing their job.”