UK police faced criticism on Tuesday after arresting a French publisher under terrorism legislation for "obstructing" a probe allegedly prompted by recent pension reforms protests in France.
Ernest Moret, who works at left-wing French publisher Editions La Fabrique, was travelling to the London Book Fair.
He was detained by British border officers after arriving at London St Pancras railway station from Paris on Monday evening.
The Metropolitan police said they stopped him and arrested him the following day on suspicion of "wilfully obstructing a Schedule 7 examination".
Schedule 7 allows specially trained officers to search and detain individuals and goods passing through the UK's border to determine whether they may be involved or used in "acts of terrorism".
The London police force said on Tuesday afternoon their "enquiries continue" and Moret remained in custody, but by the evening updated that he had been released on bail.
The Met declined to provide any further details.
Moret's publisher and UK-based Verso Books branded his treatment "scandalous", while the National Union of Journalists (NUJ) called it "extraordinary".
In a joint statement, Editions La Fabrique and Verso Books said the officers allegedly detained him "to determine whether he was engaged in terrorist acts or in possession of material for use in terrorism".
"The police officers claimed that Ernest had participated in demonstrations in France as a justification for this act," they added, calling the stance "remarkably inappropriate" and indicative of "complicity between French and British authorities".
The publishers noted that police demanded he divulge the pin code to his phone, "with no justification or explanation offered".
"We consider these actions to be outrageous and unjustifiable infringements of basic principles of the freedom of expression and an example of the abuse of anti-terrorism laws," they said.
Moret had dozens of appointments with foreign publishers at the London Book Fair — taking place in the British capital from Tuesday to Thursday.
The NUJ's Pamela Morton added: "It seems extraordinary that the British police have acted this way in using terrorism legislation to arrest the publisher who was on legitimate business here."
Moret is the foreign rights manager for popular science fiction author Alain Damasio, as well as Editions La Fabrique.
An independent left-wing publisher, it specialises in essays by collectives, activists and philosophers.
France has been hit by months of sometimes violent protests over President Emmanuel Macron's widely unpopular pension reforms, with the left and unions staging ongoing demonstrations nationwide.
