This post has been updated.

The government’s largest sale of wild horses was to a rancher who sent almost 1,800 mustangs to slaughterhouses across the Mexican border and lied to federal officials, a new report concludes, finding lapses with a federal program that’s supposed to find the animals safe homes.

The Colorado rancher and livestock hauler admitted to investigators with the Interior Department Inspector General’s office that “probably close to all” of the horses were resold for slaughter and that he assumed they would be killed.

There was “only one place to go … to the kill plant,” Tom Davis of La Jara, Colo., told investigators, whose findings confirmed longstanding fears of animal welfare groups, wild-horse activists and officials with the Bureau of Land Management’s Wild Horse and Burro Program, which manages thousands of horses that roam wild in the West.

“Managers … failed to enforce [Bureau of Land Management] policy of limiting the sales of horses and ensuring that the horses went to good homes,” the report released late last month found.

Between 2008 to 2012, the bureau sold Davis 1,794 horses for $10 apiece. The government then spent more than $140,000 delivering the animals to him.

Davis was required by law to promise that he would not resell the horses for slaughter. According to the report, he told marketing specialists with the bureau that he would sell the horses only to landowners wanting “pasture pets” or people hoping to graze the animals on their land for tax breaks.

But he repeatedly refused to name his buyers, and for three years ending in 2012, he resold the animals to businesses that sent them across the border to Mexico, where slaughterhouses for horses are legal, investigators found.

The bureau did little to follow up on where the horses went, never attempting to verify the information Davis provided about his intentions for such a large number of horses. Investigators also found that the bureau continued to sell horses to Davis even after receiving reports that he was sending them to their deaths abroad.

Horse meat is shipped to Europe and Asia, where there is a market for it.

Investigators started looking into Davis after news reports and animal welfare groups raised questions about where he sent such a large purchase of horses, the largest in memory.

Davis, reached at his home in La Jara, declined comment.

About 58,000 wild horses and burros remained on the range as of March, and their population grows about 20 percent a year. About 47,000 that have not been adopted are cared for in off-range pastures and corrals, at government expense. The total lifetime cost for caring for an unadopted horse or burro is $48,000.

About $49 million of the Wild Horse and Burro Program’s $77 million budget in fiscal 2015 was spent on caring for the horses held in pastures and corrals, officials said.

According to the Davis report, the bureau’s marketing specialists’ performance is judged in part  on how many horses they adopt out or sell. Davis told investigators that he believed officials “had to know” what he was really doing with the horses.

“Although we found various discussions concerning allegations that Davis was sending [the] horses to slaughter,” investigators wrote, “none of these discussions yielded evidence that employees sold horses to Davis knowing that he was doing so.”

In a written response to the report, Steven Ellis, the bureau’s deputy director of operations, regretted “Mr. Davis’ deceitful actions.”

Bureau spokesman Jeff Krauss said in an e-mail that the agency “is committed to improving the health and management of wild horses and burros on federal lands in the West.  We take very seriously the findings of the [report].”

The agency has made changes to prevent similar sales, “to ensure that horses were sold only to good homes,” he said. They include limiting sales over a six-month period to four horses, “ensuring that purchasers provide appropriate care and facilities for the animals.”

The inspector general referred the Davis case to federal and state authorities in Colorado, but the report said they declined to prosecute.

“It took more than three years for the [inspector general] to confirm what we’ve always known – that the [Bureau of Land Management] sold 1,795 federally-protected wild horses to a known kill buyer who sold them to slaughter,” Suzanne Roy, director of the American Wild Horse Preservation Campaign, said in a statement. “Unfortunately, there will be no justice for these mustangs, who suffered a brutal death in Mexican slaughter plants.  No one at the [bureau] is being held accountable for this betrayal, and Tom Davis is not being prosecuted for violating his contractual obligation to not sell the horses for slaughter.”