The Immigration and Customs Enforcement agency (ICE) used an existing contract with a private prison company to reach a separate deal with the firm, without having to publicly solicit bids for a new detention center.

ICE and the Corrections Corporation of America (CCA) agreed on the four-year, $1 billion no-bid deal in 2014, to rapidly implement an Obama administration initiative designed to deter the arrival of asylum seekers from Central America.

The terms of the agreement were reported on Monday in an investigation published by The Washington Post.

The paper said that the deal was hastily struck after Secretary of Homeland Security Jeh Johnson determined that the US “could cut down the surge [of migration] only by demonstrating that asylum seekers wouldn’t receive leniency.”

“This whole thing [was] building and reaching an unsustainable level,” former Johnson chief of staff, Christian Marrone, told the Post. “We had to take measures to stem the tide.”

The paper noted that those seeking asylum in the US, “until two years ago, had rarely been held in detention.”

“They instead settled in whatever town they chose, told to eventually appear in court,” the Post said. Johnson had described incarceration as being part of a broader “aggressive deterrence strategy.”

To avoid public scrutiny and bureaucratic delays, the deal between ICE and CCA hinged on an existing agreement between the company and the town of Eloy, Arizona.

The for-profit prison company had, since 2006, been running a detention facility for undocumented men in the town. An amendment to the deal — and another previously-existing contract between Eloy and ICE — enabled CCA to quickly open a new facility, 1,000 miles away and out of state.

Eloy officials agreed, its city manager told the Post, despite “some reluctance because of the optics.” CCA subsequently opened the South Texas Family Residential Center, in the town of Dilley. The facility holds 2,400 beds.

Experts on the federal contracting process told the Post that “while the government can avoid bidding laws in urgent or national security cases, they had never before seen a facility in one state created with the help of a recycled contract from another.”

Though the plan escaped the normal contracting oversight, a federal judge determined in 2015 that Johnson’s “aggressive deterrence strategy” is, in fact, illegal, ruling that ICE can’t hold people in detention “simply to deter others.”

And in another blow to Johnson’s initiative, another judge ruled that undocumented migrant children had to be released after being detained by the US government “without unnecessary delay.”

“As a result, stays at Dilley have shortened,” the Post noted. “Families are typically released in a matter of weeks, after women pass an initial interview establishing they have a ‘credible’ reason to fear returning home.”

Johnson’s “deterrence” appears wholly ineffective outside of judicial review. The number of “family units” detained at the US-Mexico border over the past 12 months has increased to 66,000, as the Post remarked — up from 61,000 during the same time frame two years ago.

In 2015, the Dilley detention center made CCA 14 percent of its revenue “while recording record profit.” The company currently runs 74 detention centers.

Migration from Central America to the US has been driven in recent years by gang violence and persistent widespread poverty — particularly in Honduras, Guatemala and El Salvador.