U.S. Senator Jon Tester is demanding transparency from the Indian Health Service (IHS) following their refusal to hold themselves accountable by making public a report that details their decades-long mishandling of convicted sex-offender Dr. Stanley Patrick Weber.

In a recent letter to Secretary of Health and Human Services Secretary Alex Azar, Tester called on IHS—which operates within the Department of Health and Human Services—to uphold their commitment to transparency for the sake of the victims the agency failed to protect in Browning, Montana and Pine Ridge, South Dakota.

“Time and time again IHS protected Dr. Weber, allowing him to continue working with children despite complaints of abuse,” wrote Tester. “…IHS failed to protect the very people it is intended to serve. [They] must be held accountable, and the findings from the independent investigation will be crucial to ensuring that these crimes never occur again.”

Tester continued: “I strongly urge you to release a version of this report to the public.”

Tester’s letter comes on the heels of an IHS statement in which the agency refused to disclose a report that identifies the officials responsible for mishandling Dr. Weber’s case as he abused Native American boys over the course of multiple decades. Citing a law set up to protect medical reviews, the agency is declining to hold themselves accountable to victims, their families, and their communities by shuttering the report from the public.

The decision to keep the report confidential quickly followed Dr. Weber’s conviction for sexual abuse last month, for which he was sentenced to five lifetime prison terms. Tester quickly slammed the agency for their lack of transparency.

Tester also recently joined a group of his colleagues from the Senate Indian Affairs Committee in demanding IHS release the full, unredacted report to members of Congress and their staff for review. In a letter to Secretary Azar, the Senators wrote:

“There is no legal basis for the IHS to withhold or limit access to its unredacted findings from review by the congressional committee of jurisdiction. As a coequal branch of government, we expect full transparency from your Department and the agency regarding this report and on all instances of patient abuse. HHS and IHS must uphold their commitment to transparency on the Weber incident and issues of patient abuse.”