A dissident organisation known as the Cheollima Civil Defense (CCD) says, it orchestrated the raid, by sharing "information of enormous potential value" with the FBI, to end illicit activities rampant in North Korea's foreign missions.
A shadowy group committed to overthrowing North Korean leader Kim Jong-un claimed responsibility Wednesday for a raid on the reclusive nation's embassy in Madrid last month, saying it shared "information of enormous potential value" with the FBI.
The incident had been shrouded in mystery, but a dissident organisation known as the Cheollima Civil Defense (CCD) said Wednesday it had orchestrated the raid to end illicit activities rampant in North Korea's foreign missions.
The claim comes after a Spanish court named Adrian Hong Chang, of Mexican nationality, as being the leader of the group - the first official account of the incident, which came days before the summit between Kim and US President Donald Trump in Hanoi.
Previous media reports said a group of men burst into the diplomatic mission and roughed up employees before making off with documents and computers.
According to investigating judge Jose de la Mata, two of the assailants took the embassy's commercial attache to an underground room and urged him to defect, which he refused.
CCD denied using any violence, saying in a statement on its website: "We were invited into the embassy, and contrary to reports, no one was gagged or beaten.
"Out of respect for the host nation of Spain, no weapons were used. All occupants in the embassy were treated with dignity and necessary caution."
The group, which offers to assist people attempting to defect from North Korea - emerged in 2017 when it posted an online video of the son of the North Korean leader's assassinated brother, saying it had guaranteed his safety.
Last month the group declared itself a government-in-exile for the North called "Free Joseon", using an old name for Korea.
It said the raid had no links to the Hanoi summit - which ended abruptly with no agreement - and that no other governments were involved until after the event.
"The organisation shared certain information of enormous potential value with the FBI in the United States, under mutually agreed terms of confidentiality," the statement added.
Speculation over the identity and motive of the assailants had swirled in the media, with Spanish daily El Pais suggesting links to the CIA.
According to an El Pais report, Spain had asked for clarification from the CIA but the US spy agency denied any involvement.
Spanish authorities said the response was "not very convincing," adding that the CIA acted "in probable co-operation" with South Korean intelligence services.
Seoul's unification ministry, which handles inter-Korean relations, declined to comment.
Little is known about CCD and it is unclear who is behind the organisation, although some have speculated it has links to South Korea's spy agency.
It is named after a mythical winged horse.
In the past, the group has said it responded to urgent requests for protection from "compatriots" and has thanked countries including the Netherlands, China and the United States for their help.