The world was not aware for a number of years, for a number of reasons.

The initial abductions were carefully planned and executed by a practiced team of operatives; by that time they had abducted a number of people from different countries. Their operations were likely known by intelligence agencies (they had attempted and failed to abduct Baek Geon-u and his wife Yoon Jeong-hee six months before), but there was little public proof.

After Choi's abduction, civilian investigators and the press focused on Shin's possible involvement, and, while he suspected an associate with North Korean ties, he was himself abducted months later without discovering the agents who had infiltrated his organization.

Shin was then imprisoned by Kim for several years, and he made two escape attempts during that time, for which he was severely punished. For his third attempt, he chose to feign collaboration with the Kim regime and began making the films they desired. He and Choi claimed publicly to have defected voluntarily, while privately they planned their escape and gathered evidence to clear their names.

As they gained Kim's trust they were allowed more travel and contact with the outside world, and they passed photographs and an audio recording of a conversation with Kim to a Japanese film critic, Kusakabe, who passed this evidence to Japanese and Korean media.

This revelation was not supposed to happen until much later, for obvious reasons, and it nearly defeated their plan. The reasons why it didn't are not fully known; it's possible that Kim believed that the evidence was manufactured by a third party, or he may have decided to continue with the charade, confident in his ability to contain them.

In any case, at Kim's urging, Shin and Choi had a press conference in Belgrade to deny the evidence and repeat their claim to have defected voluntarily.

They continued filming on location in Europe and finally escaped during a trip to Vienna.

It was only after they reached safety that they were able to tell the whole story, which remained consistent until their deaths.