A group known as shadowy is committed to ousting North Korea’s leader Kim Jong-un has claimed it was behind a raid last month at the North Korean embassy in Spain.
Cheollima Civil Defense, a self-styled human rights group, reportedly carted away with computers, a phone and hard discs.
The break-in occurred just days before a key summit between US President Donald Trump and North Korean leader Kim Jong-un in Hanoi, Vietnam.
The group has denied using force, saying it was “not an attack”.
However, a Spanish high court judge said the 10 assailants shackled, beat and interrogated embassy staff in the incident on 22 February.
It remains unclear why the raid took place. Cheollima wrote online that it had “responded to an pressing situation in the Madrid embassy”.
It said it had “shared information of large potential quality” with the FBI, the US intelligence agency, “under mutually agreed terms of confidentiality”.
On Tuesday Judge José de la Mata raise a secret decree on the investigation, according to a document from Spain’s High Court.
The break-in began at 16:34 (15:34 GMT), it said, and most of the intruders fled at 21:40.
The judge said the group had “identified themselves as members of a human rights movement seeking to liberate North Korea”.
One of their members, named as Adrian Hong Chang, allegedly gained entry to the embassy by asking to see the commercial attaché, whom he claimed to have met previously to discuss business matters. His accomplices burst in once he was inside, the judge said.
The group are indicted of quizzing the attaché and trying to persuade him to defect. When he refused, they left him tied up in the basement, the judge said.
Two other members of the break-in group were named as US citizen Sam Ryu, and a South Korean, Woo Ran Lee.
The judge said that embassy staff were held hostage for several hours.