The government wasted more than $41 million by sending illegal immigrants home on empty charter flights in the last 3 ½ years, according to a Department of Homeland Security report released earlier this month. The report, titled “ICE Air Transportation of Detainees Could Be More Effective,” was first reported Monday by the Washington Post.

The DHS inspector general’s office said in the April 9 report that Immigration and Customs Enforcement (ICE), “may have missed opportunities to improve the program’s overall effectiveness even though it has identified some ways to reduce costs associated with detainee transportation.” ICE’s air program had poor planning and management, which contributed to the wasteful spending, the report said. (ICE is the federal agency that enforces laws on border control, customs, trade and immigration. It is overseen by DHS.)

“As a result, ICE Air operated charter flights with empty seats and could have realized cost savings of up to $41.1 million upon determining optimum flight capacity,” the report’s authors found. The inspector general’s office said ICE needs “formal policies and procedures for its air transportation program” and should “ensure adequate staffing, complete and reliable program data, and perform an analysis of operations to identify factors affecting efficiency.”

ICE’s air program pays about $8,419 per flight on average, regardless of whether the flights are full or not, DHS said. From October 2010 to March 2014, ICE spent $464 million on charter flights, the report found. The flights were either within the United States to shuffle the illegal immigrants between ICE field offices or to the immigrants' countries of origin if they were from the Caribbean, Central America or South America. About $116 million worth of flights during that span didn’t fill every seat and flew at less than 80 percent capacity.

A DHS review of more than 7,000 flights found that nearly 24,000 illegal immigrants were listed as being dropped off or picked up from locations not along the route of the charter flight, including 54 Nicaraguan illegals where Nicaragua was not on the flight route.