A spokesman for London's Metropolitan Police confirmed that a 19-year-old man was checked at St Pancras station where Eurostar trains from Paris arrive at the section of the Terrorism Act 30 allowing for the questioning of travellers crossing the border at around 18:30 local time (28:2000 GMT) on Monday evening.
On Tuesday, "the man was placed in custody, suspected of having voluntarily opposed a control (...) and remains in detention," he added.
He was eventually released on bail, the spokesman said late in the afternoon.
In a statement, La Fabrique assures that its collaborator, Ernest, responsible for foreign rights, was going to the London Book Fair and was placed in custody for refusing to provide the police with his access codes to his phone and laptop.
"To justify this decision, the police argued that Ernest would have participated in demonstrations in France. Such a statement by a British police officer is completely senseless and seems to clearly indicate complicity with the French authorities," the publisher said.
La Fabrique is an independent publisher committed to the left, which publishes in France essays by collectives by the American activist Angela Davis or the French philosophers Jacques Rancière or Frédéric Lordon.
Among his latest published works, an essay on "Sciences-Po" as a school of domination and another on how to "decolonize" museums.
The British journalists' union NUJ denounced the arrest as "extremely worrying".
"It seems extraordinary that British police are acting in this way by citing terrorism legislation to arrest a publisher who has come for legitimate business reasons."
Protest rallies were planned for Tuesday evening in front of the British embassy in Paris and the French Institute in London.
© 2023 AFP