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.
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.
"The organization shared certain information of enormous potential value with the FBI in the United States, under mutually agreed terms of confidentiality," the statement added.
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.
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.