As the Senate prepares for Thursday’s hearing on plummeting deportation rates and increasing criminal alien releases, an anonymous whistleblower is now speaking out about alleged waste and abuse of taxpayer funds within a federal immigration enforcement agency.

The whistleblower says that these “abuses clearly threaten” the ability of the nation’s immigration officers to enforce immigration law and keep the American people safe.

The anonymous whistleblower, who serves as a member of a federal immigration agency, has filed a report with the Office of Special Counsel alleging fraud, waste, and abuse within the Enforcement and Removal Operations (ERO) division of Immigration and Customs Enforcement (ICE). In the report, which has been obtained exclusively by Breitbart News, the whistleblower estimates that the waste could be costing U.S. taxpayers up to $27.5 million annually, and could involve up to 500 federal agents.

“The situation I now report has been ongoing for years, and the abuses clearly threaten the mission readiness of a federal law enforcement agency with a key public safety and national security mission,” the whistleblower writes. “The estimated amount of fraud, waste and abuse in one year is $12.5M – $27.5M. The estimated number of ICE ERO supervisors involved is between 250-500.”

The whistleblower’s report emerges amid new findings documenting how interior deportations were down 62 percent in 2015 from 2012, according to data from the Department of Homeland Security. At the same time, the agency responsible for removals, Immigration and Customs Enforcement (ICE), has seen its detention and removal budget grow by 25 percent over that same time period—from $2.75 billion in FY2012 to $3.43 billion in FY2015. The Senate Immigration Subcommittee separately found that ICE removed “less than one percent of the number of aliens who overstayed their visas in FY 2015 alone.”

In the report to the Office of Special Counsel, the whistleblower writes:

Each year ICE ERO [Enforcement and Removal Operations] leadership requests funding from Congress that includes millions of dollars in expenses for law enforcement vehicles, fuel and maintenance costs. However, ICE ERO leadership is intentionally concealing from Congress each year in its budget requests that ICE ERO leadership intends to spend millions of taxpayer dollars from ICE ERO’s law enforcement budget (specifically funding for law enforcement vehicles) on management perks, not the agency mission or police work as ICE leadership is falsely leading Congress and the American public to believe.

The whistleblower explains that the vehicles are not being given to agents seeking to do their job, but are instead being given to management for personal use. The whistleblower singles out the role of Executive Associate Director Thomas Homan in particular. Homan will be testifying before Congress during Thursday’s hearing. The whistleblower writes:

Unmarked vehicles are required equipment for officers on the street involved in tracking, surveilling and apprehending at large criminals and fugitives, as well as on-call duty officers required to respond to requests for assistance 24 hours a day. However, ICE ERO, under the leadership of Director Thomas Homan, is taking hundreds of these unmarked law enforcement vehicles away from law enforcement operations and instead providing them to managers for non-law enforcement personal usage amounting to millions in hidden ‘management perks’ and pay bonuses.

The whistleblower says that this comes at a direct cost to U.S. taxpayers:

Taxpayers and Congress are unwittingly paying for hundreds of ICE managers to each have their own vehicle valued at $50,000-$70,000 for personal travel and use not authorized for other federal employees. Additionally, each manager is provided a government fuel card so that he/she is able to purchase essentially unlimited amounts of taxpayer funded fuel. Conservative estimates indicate that taxpayers are paying approximately $5,000 per manager each year in fuels costs, not including unknown costs for tires, oil changes, car washes and other maintenance. These managers have no mission need to have these vehicles and instead use them primarily to commute between work and home each day. Meanwhile, officers in the field don’t have vehicles to perform ICE ERO’s law enforcement mission because the vehicles have been issued to ICE managers for their personal use and financial benefit.

The whistleblower continues:

ICE ERO managers view having a free vehicle and free fuel for personal use as a birthright. Of course it’s not ‘free’ as it comes at great cost to the government and taxpayers. So out of control is the entire process, that when a new vehicle is issued to an ICE ERO office, managers frequently have directed that managers have first choice to upgrade to the new vehicle and only hand-me-down used vehicles are provided to officers for performance of the agency mission. Any employee pointing out that managers are improperly using the vehicles, or that the agency’s mission is being negatively impacted by these practices, will face severe reprisal. Officers and employees in the field are too afraid to report the fraud, waste, abuse and misconduct by their own managers. Almost every ICE ERO manager is involved, from ERO Director Thomas Homan and his staff, to all 24 ERO Field Office Directors and their management staff… Because ICE and DHS cannot be trusted to properly investigate themselves or hold managers accountable, this report will be provided to the media and other entities for oversight. Congressional hearings… should be conducted as well.

In the report, the whistleblower breaks down the cost estimate for U.S. taxpayers:

It is estimated that approximately 250–500 ICE ERO managers are currently assigned a government vehicle and fuel card but have no mission related justification for possessing either. These vehicles are provided to managers for their personal use, such as driving back and forth from home to work. If each assigned vehicle has an estimated purchase cost of $50,000, the cost of vehicles inappropriately assigned to ICE ERO managers at any given time is between $12.5M – $25M. Annual Fuel costs are estimated between $1.25M – $2.5M. Again, these estimates do not include tire replacement, oil changes, car washes and other expenses also frequently charged to taxpayers by ICE ERO managers. Additionally, more vehicles are necessary and being purchased by ICE ERO due to the vehicle shortages created solely by management abuse of the vehicles ICE ERO already has in its inventory. These unnecessary purchases will likely cost taxpayers millions.

The whistleblower tells the Office of Special Counsel that the decision to come forward could have consequences for enforcement agents trying to do their job:

ICE managers will retaliate. ICE leadership and managers will take their anger out on the workforce once this report becomes public and investigations begin (if an investigation is conducted). ICE ERO managers will severely restrict usage or take vehicles from officers who have a bona fide law enforcement need. These same managers have already proven their disregard for their own officers and the agency’s mission by taking hundreds of vehicles away from law enforcement operations simply for their own financial benefit. The agency mission, public safety and national security are not the priority for ERO leadership or management; they will not hesitate to further harm operations as part of their retaliation. I am hopeful that you and your staff, and indeed members of Congress, will assist in preventing that from happening… If a rank and file officer or employee at ICE ERO misled Congress, misappropriated funds, misused government equipment or otherwise displayed this type of unethical behavior for their own financial benefit at the expense of the law enforcement mission and taxpayer funds, their career would be over. With many years of service as a federal employee, somehow I doubt anything significant will be done to end these practices or hold those involved accountable. I hope that your office and members of Congress prove me wrong.

Chairman of the Senate Immigration Subcommittee, Jeff Sessions, has previously documented how President Obama has systematically dismantled immigration enforcement during his two terms in the Oval Office. Hillary Clinton has pledged that if elected, she will continue President Obama’s immigration agenda. Clinton has pledged to essentially freeze deportations, defend and extend President Obama’s unconstitutional executive amnesties, end all family detention at the border, and give Obamacare to illegal immigrants.