SEOUL, South Korea — South Korea’s truth commission has concluded that the government bears responsibility for facilitating a foreign adoption program rife with fraud and abuse, driven by efforts to reduce welfare costs and enabled by private agencies that often manipulated children’s backgrounds and origins.

The landmark report released Wednesday followed a nearly three-year investigation into complaints from 367 adoptees in Europe, the United States and Australia, representing the most comprehensive examination yet of South Korea’s foreign adoptions, which peaked under a succession of military governments in the 1970s and ’80s.

The Truth and Reconciliation Commission, a government-appointed fact-finding panel, said it confirmed human rights violations in 56 of the complaints and aims to review the remaining cases before its mandate expires in late May.

However, some adoptees and even a senior investigator on the commission criticized the cautiously written report, acknowledging that investigative limitations prevented the commission from more strongly establishing the government’s complicity.

That investigator, Sang Hoon Lee, a standing commissioner, also lamented the panel’s decision-making committee’s 5-4 vote on Tuesday to defer assessments of 42 other adoptees’ cases, citing a lack of documentation to sufficiently prove their adoptions were problematic. Lee and the commission’s conservative chairperson, Sun Young Park, did not specify which types of documents were central to the discussions.

However, Lee implied that some committee members were reluctant to recognize cases in which adoptees had yet to prove beyond doubt that the biological details in their adoption papers had been falsified — either by meeting their birth parents or confirming information about them.

Most Korean adoptees were registered by agencies as abandoned orphans, although they frequently had relatives who could be easily identified or found, a practice that often makes their roots difficult or impossible to trace. Government data obtained by The Associated Press shows less than a fifth of 15,000 adoptees who have asked South Korea for help with family searches since 2012 have managed to reunite with relatives.

Lee said the commission’s stance reflects a lack of understanding of the systemic problems in adoptions and risks excluding many remaining cases.

“Personally, I find yesterday’s decision very regrettable and consider it a half-baked decision,” Lee said.

After reviewing government and adoption records and interviewing adoptees, birth families, public officials and adoption workers, the commission assessed that South Korean officials saw foreign adoptions as a cheaper alternative to building a social welfare system for needy children, including those born to poor parents or unwed mothers.

Through policies and laws that promoted adoption, South Korea’s military governments permitted private adoption agencies to exercise extensive guardianship rights over children in their possession and swiftly transfer custody to foreign adopters, resulting in “large-scale overseas placements of children in need of protection,” the commission said.

Authorities provided no meaningful oversight as adoption agencies engaged in dubious or illicit practices while competing to send more children abroad. These practices included bypassing proper consent from biological parents, falsely documenting children with known parents as abandoned orphans, and switching children’s identities, according to the commission’s report. It said the government failed to ensure that agencies properly screened adoptive parents or prevent them from excessively charging foreign adopters, who were often asked to make additional donations beyond the standard fees.

The commission recommended that the South Korean government issue an official apology over the problems it identified and develop plans to address the grievances of adoptees who discovered that the biological origins in their adoption papers were falsified. It also urged the government to investigate citizenship gaps among adoptees sent to the United States — the largest recipient of Korean children by far — and to implement measures to assist those without citizenship, who may number in the thousands.

South Korea’s government has never acknowledged direct responsibility for issues surrounding past adoptions, which have drawn growing international attention amid criticism that thousands of children were carelessly or unnecessarily separated from their biological families. The Ministry of Health and Welfare, the government department that handles adoption issues, did not immediately comment on the commission’s report.