Niigata, Japan ? At first, Misa Morimoto thought her 20-year-old twin sister, Miho, had just decided to suddenly go off on a trip. Four days later police called to say they had found Miho’s bag and driver’s license on a secluded beach.

After nearly 20 years, Morimoto may now be closer to finding out what happened. And the beach where her belongings were found provided a key clue – it was the scene of a confirmed abduction years before.

Since North Korea’s surprise confession two months ago that its spies abducted 13 Japanese in the 1970s and ’80s, Japanese police are re-examining dozens of missing persons cases and now believe North Korea may have abducted as many as 80 more people than it admitted.

Morimoto’s sister, police say, is probably among them.

“I’ve spoken to several experts on North Korea about her case, and they say there is no doubt she was also abducted. More and more, it seems to me that was the case,” Morimoto said.

Other suspected victims include a 27-year-old agriculture engineer who disappeared while heading back to his dormitory after dinner, a 29-year-old noodle shop employee who vanished on a trip to Europe and a 51-year-old carpenter who had gone to Tokyo to look for work.

The admissions by communist North Korea have raised hopes that more families will finally get some closure. But politics are threatening to close the door on further investigations.

Though North Korea’s initial confession that it abducted people to teach the Japanese language and culture to North Korean spies, and its decision to let five surviving kidnap victims revisit Japan, were hailed as a big step toward diplomatic normalization, anger and distrust have set in again.

Tokyo is refusing to return the five and is demanding their children and the American husband of one be repatriated as well. Pyongyang has accused Japan of breaking a promise that the homecoming would be brief.

Talks to establish ties are on hold, and North Korea has threatened to stop honoring a moratorium on its test launches of long-range missiles.