A man in his 80s, who was wrongfully imprisoned for being part of a so-called “European espionage operation ring,” was found not guilty in a retrial, 55 years after his initial guilty verdict.

According to legal insiders on Wednesday, the Supreme Court last month finalized the original trial verdict from earlier this year, which acquitted the falsely accused man surnamed Kim, on charges of violating the National Security Act and the Anti-Communism Act.

Kim was a graduate student at Korea University and was indicted on charges of contacting a North Korean agent to deliver instructions, and reading books on socialism while studying abroad in Cambridge, England.

Kim was sentenced to seven years in prison in a 1969 trial and requested a retrial in 2022. The Seoul High Court found him not guilty in February.

Professor Park No-soo and lawmaker Kim Kyu-nam, who were falsely accused of leading the “European espionage ring,” were sentenced to death by the Supreme Court in 1970, and executed in July 1972.