The remains of tens of thousands of individuals taken by the Smithsonian Institution without consent should be proactively returned to their families and communities, a task force convened by the world-renowned museum complex has concluded.

If adopted into policy, the recommendations outlined by the 15-person task force would represent a historic shift for the Smithsonian, significantly broadening its repatriation efforts.

The recommendations, released Wednesday, follow a Washington Post investigation that revealed that the Smithsonian National Museum of Natural History holds more than 30,700 sets of human remains, largely taken from graveyards, battlefields, morgues and hospitals in more than 80 countries in the late 19th and early 20th centuries. The collection includes 254 human brains housed in a storage facility in suburban Maryland, most of them taken from people of color to further now-debunked theories on racial differences.

While the Smithsonian is mandated under a 1989 federal law to offer to return the remains of Native American, Native Hawaiian and Alaska Native people to their descendants and communities, the legislation is silent on all other remains, leaving thousands of body parts in limbo.

But in Wednesday’s report, the task force proposed that the Natural History Museum establish a new staff that would be responsible for returning remains that are not covered by the federal law - a policy that experts say could prompt other museums worldwide to follow suit. The report also recommended streamlining the process for returning Native American remains and providing additional funding for that effort.

The task force - made up of Smithsonian officials and outside experts - called the collection an “unfortunate inheritance, a racist legacy that burdens the Smithsonian and prolongs this injustice.”

“While much of this collecting of human remains was done by curators and individuals long dead, it occurred at the Smithsonian and relied on the Smithsonian’s resources, reputation, and influence,” the task force wrote. “The original intent of collecting these human remains was morally abhorrent, because it sought to prove the superiority of white people and their descendants to Native Americans, African Americans, and others through scientific means that are now thoroughly discredited.”

Officials said the policies laid out in the report could be adopted by this fall.

Kevin Gover, a co-chair of the task force and the Smithsonian’s undersecretary for museums and culture, said the report reflected a drastic change in the way the Smithsonian has grappled with human remains that were collected during a different era.

“We inherit what our predecessors did at the Smithsonian, and that means we also inherit the obligation to doing what we can to put things right,” said Gover, a former director of the Smithsonian’s National Museum of the American Indian and a citizen of the Pawnee Tribe of Oklahoma. “This institution is now 177 years old, and like any institution of that age, we have a lot to answer for on matters of race,” he added.

The Post last year examined the grisly legacy of Ales Hrdlicka, who led the physical anthropology department at the U.S. National Museum, the precursor to the Natural History Museum, for most of the first half of the 20th century. Hrdlicka believed in white superiority and amassed thousands of bones and other body parts at the museum to further his theories on the anatomical differences between races.

The Post found that the museum had failed to return the vast majority of human remains in its possession, and that families and communities were required to formally petition for their return, even though many had no idea they had relatives with remains in the collection.

As of December, museum officials had returned or offered to return more than 6,300 sets of human remains - the vast majority belonging to Native Americans, as required by federal law.

In response to The Post’s reporting, Lonnie G. Bunch III, the Smithsonian’s secretary, published an op-ed apologizing for the way the institution had collected human remains and said his goal was to return as many remains as possible.

According to the new report, around half of the individuals whose remains are still stored by the Smithsonian are Native American and 2,100 are African American. Almost 6,000 of the individuals are named, “either in full, partly, or by their initials.”

In recent years, museums and universities across the United States have undergone a reckoning over the thousands of Native American remains in their collections that federal laws forced them to address in the 1990s after years of activism from Indigenous communities. The Smithsonian, which has one of the largest collections of human remains in the world, is governed by a 1989 repatriation law. Other museums and universities are covered under another law - the Native American Graves Protection and Repatriation Act - that was recently strengthened by new Department of the Interior regulations.

After The Post began reporting on the Smithsonian’s collection of human remains, Bunch last year convened the task force to determine how the Natural History Museum and the National Museum of the American Indian would handle the human remains in their holdings.

The report was blunt about the origins of the collection, outlining the practices of anthropologists like Hrdlicka who exploited disadvantaged populations to collect remains with the intention of comparing races and proving the superiority of White people.

The institution last year paused research on human remains unless approved by top Smithsonian officials. In its report, the task force urged the institution to allow research on human remains only after officials have obtained permission from descendants, communities or institutions related to the individuals - with exceptions for remains from certain ancient communities.

The task force also said the Smithsonian should prioritize returning the remains of people whose names are known by the museum, and that identifying remains from specific cemeteries, burial grounds and university or medical school collections could speed up the process of returning or burying them. It also suggested developing a process to bury or memorialize remains that are not easily identifiable.

C. Timothy McKeown, an adviser for the National Association of Tribal Historic Officers who worked on the implementation of repatriation policy at the Department of the Interior for 18 years, called the report a “major policy shift” for the Smithsonian that could go further than the repatriation efforts of many museums worldwide.

“I think this definitely will have an impact,” he said. “I think many museums ... will look at it and say, ‘Hey, the Smithsonian’s doing this. Don’t you think we ought to do it, too?’”

The report acknowledged that the institution, which receives about two-thirds of its funding from Congress, would need to seek more congressional and philanthropic support to complete its mission. Gover said securing additional money from Congress would be difficult, but that the institution has been exploring opportunities with philanthropic organizations.

The Post’s investigation last year into the Smithsonian’s collection of human brains and other body parts found that of the more than 280 brains it gathered, the institution has returned just five to their families or descendant communities.

After The Post began reporting, the Smithsonian reached out to the Philippines to discuss repatriating remains of Filipinos within the collection. In August, the Natural History Museum returned the brain of a Sami Alaskan woman, Mary Sara, to her relatives after The Post informed them that the museum held her remains. That month, the family buried her brain, collected by the institution after her death from tuberculosis in 1933, in her grave in Seattle.

Rachel Twitchell-Justiss, Mary Sara’s distant relative, said she believes “talk is cheap” and wants to see the institution follow through on the recommendations laid out on Wednesday. “My hope is that they just do whatever they do with the utmost respect,” she said.

The Post also found that 74 of the brains gathered by the museum - more than a quarter of the brain collection - came from the D.C. area, including 48 brains taken from African Americans. One of those individuals was Moses Boone, a 21-month-old Black child who died of tuberculosis at Children’s Hospital in 1904. Michelle Farris, a distant relative of Boone, was unaware that her family member’s brain was held by the Smithsonian until informed by The Post.

Natural History Museum officials recently reached out to Farris to apologize. Farris said she will soon start the process to request the brain’s return to the family and plans to bury it in the historic Mount Zion Cemetery, where the rest of the toddler’s remains lie in an unmarked grave.

Other local communities have called for the Smithsonian to return remains, as well. In January, Del. Eric Zehr (R) introduced a bill in the Virginia House of Delegates to request that the Smithsonian return all of its Virginia remains to descendants and compensate families and tribes for funeral and burial expenses. While the bill didn’t pass, a member of Zehr’s staff said he may reintroduce it and is seeking congressional support.

As part of its reporting, The Post also published a public database of records that offered the most comprehensive overview of the Smithsonian’s human remains collection to date. When Eden Fineday, a member of the Sweetgrass First Nation in Canada and the publisher of the media outlet IndigiNews, searched through the database, she found that the Smithsonian had collected the skull of her great-great-grandfather, Little Poplar, in 1894.

Horrified, she contacted the Natural History Museum to learn more about the remains. The museum will fund a trip for her to visit her great-great-grandfather’s remains next month, and Fineday said she hopes to eventually bury them.

Fineday said she found the task force’s recommendations “basic,” but she was hopeful that the institution’s public statements would help ensure that human remains were returned to their rightful heirs.

“It’s all about the political will,” she said. “It sounds like they want to do it, and that’s probably 99.9 percent of the challenge.”

Andrew Ba Tran contributed to this report.