The then puppet Central Intelligence Agency took Kang U Gyu, Korean businessman from Japan, into custody, branding him as a "spy disguised as a member of a Koreans' investment enterprise, and detained ten other citizens on charges of "aiding" him in March 1977.

The Agency sentenced Kang to death in June 1977 and others to up to 12 years in prison.

The victims and their families have waged unrelenting struggle demanding a probe into the truth behind the spy case fabricated by the Agency.

The Supreme Court in November 2013 admitted that the then Central Intelligence Agency extorted false confession from victims by torture after illegally arresting them, and requested the Seoul High Court to do retrial.

At the retrial in December 2014, the Seoul High Court pleaded "no ability to prove evidence as for the confession of those accused" and confirmed that all of those charged were not guilty, and the Supreme Court also passed the same judgment.