TOKYO (Reuters) - For two decades after 13-year-old Megumi Yokota vanished on her way home from school one November evening, Japanese police called her parents whenever they found an unidentified body.
Unimaginably, the teenager had been abducted and taken to North Korea, her mother told a U.N. Commission of Inquiry panel in Tokyo on Thursday - but there was no clue what had happened to the cheerful girl who liked to sing until reports began to emerge in 1997 of the presence of Japanese in North Korea.
"Up until then, whenever they found a body, or there was a murder, or a skeleton got snagged in the fishing net of a boat, anywhere in Japan, the police would get in touch with us," Sakie Yokota told the commission, the first time Pyongyang's human rights record has been looked at by an expert panel.
"We lived in a sadness that I thought would drive us mad."
Megumi is one of 13 Japanese that Kim Jong-il, the late father of current leader Kim Jong-un, admitted in 2002 had been kidnapped in the 1970s and 1980s to help train spies. Pyongyang says eight of them are dead, including Megumi, but Japan wants more information.
The dispute over the abductees has been a major stumbling block in normalizing relations between the two countries and progress has stalled in recent years, though Japanese Prime Minister Shinzo Abe has expressed hope that movement may be possible under the third generation of the founding Kim family.
The North denies that it abuses human rights and has refused to recognize the commission, denying access to investigators.
The nightmare began for the Yokotas in 1977, when Megumi failed to return from playing badminton at school.
"We felt a huge fear," Sakie told the U.N. panel, her voice shaking. "I took her little brothers by the hand and we ran out in the dark, looking on beaches and calling Megumi, Megumi."
Searches by police and sniffer dogs showed she had reached a street corner just blocks from her home, then the trail went cold.
Following the 2002 visit to North Korea by former prime minister Junichiro Koizumi at which Pyongyang admitted the abductions, it came out that Megumi had married and had a child, though North Korea said she had died some years previously.
Later Pyongyang sent back bones that they said were Megumi's, but DNA testing found they were those of a man.
"Three photos came back with the bones, our first sight of Megumi as an adult. I cried and cried," Sakie said. "Both my husband and I apologized for not being able to help her."
Commission head Michael Kirby, a retired Australian judge, told Reuters that the goal of the inquiry, which will be submitted by the end of the year, was to give a voice to the Yokotas and similar families.
At the very least, it wants to give the families the peace of knowing what happened.
"Who else has engaged in kidnapping - and not kidnapping of nuclear scientists, Internet experts - the kidnapping of a chef, a guard, a schoolchild, a housewife whose two young children were left crying in a crèche?" he said.
"It certainly calls out for evidentiary answers. If the evidentiary answers are not given, North Korea will only have itself to blame if the commission of inquiry and the world community believes what these witnesses have told."
Sakie Yokota said that Megumi would turn 49 in October.
"She was just 13 years old," she said. "Did they mistake her for an adult and take her, or did they have something else in mind? We'll never know. Until she comes home."
Additional reporting by Leng Cheng in Tokyo; Editing by Nick Macfie