The FBI on Wednesday arrested two former senior officials who served in the administration of Puerto Rico Gov. Ricardo Rosselló, leading the chairman of the House committee that oversees Puerto Rico to call for the governor to step down.

The arrests also spurred concerns on Capitol Hill about the billions of dollars in aid that Congress has approved for the island.

The federal indictment says the former officials illegally directed federal funding to politically connected contractors. The arrests come about a month after Congress approved a controversial disaster aid bill that earmarked additional funding for Puerto Rico’s recovery from Hurricane Maria in 2017. The aid was tied up in part because President Trump called island officials “incompetent or corrupt.”

Rep. Raúl M. Grijalva (D-Ariz.), chairman of the Natural Resources Committee that oversees Puerto Rico, called on Rosselló to resign amid the ongoing federal investigation.

“We’ve crossed that crucible now,” said Grijalva, who later reiterated on Twitter that he supports Rosselló's resignation. “The restoration of accountability is so key going forward.”

Six people were charged in the 32-count indictment. They include Julia Keleher, who served as Puerto Rico’s education secretary until April, and Ángela Ávila-Marrero, who was the executive director of the Puerto Rico Health Insurance Administration until late June.

“Keleher and Avila-Marrero exploited their government positions and fraudulently awarded contracts funded with federal monies,” U.S. Attorney Rosa Emilia Rodriguez-Vélez said in a statement. “The charged offenses are reprehensible, more so in light of Puerto Rico’s fiscal crisis.”

Prosecutors said Rosselló was not involved in the investigation, according to the Associated Press. The governor said on Twitter he had cut short a vacation to return to the island.

A spokesman for Rosselló did not respond to requests for comment. The U.S. attorney in Puerto Rico also told CBS News that Rosselló is not being investigated in relation to Wednesday’s arrests. On twitter, the governor said his administration would fight corruption in all its forms and that nobody is above the law.

The island’s allies fear that the arrests will give Trump greater justification for curtailing badly needed aid to the island. San Juan Mayor Carmen Yulín Cruz, a political opponent of the governor, said poor people on the island who still need federal aid will be the victims of the corruption charges if they lead to reductions in federal spending. The allegations “do not represent what the people of Puerto Rico are about,” she said.

“The governor of Puerto Rico and his administration have now given President Trump the ammunition he needed,” Cruz said.

Congress has approved $42 billion for the island’s recovery, but only about $14 billion of that money has been spent, according to federal data.

Island officials and some congressional Democrats have complained that the Trump administration is needlessly stalling disaster relief, while Trump has said that “nobody could have done” what he has for Puerto Rico. He has argued that the island has received sufficient federal assistance.

Hurricane Maria caused thousands of deaths, as well as damage estimated between $90 billion and $120 billion, according to Federico A. de Jesús principal of FDJ Solutions, a consulting firm, and the former deputy director of the Puerto Rico governor’s office in Washington.

Puerto Rico is in the middle of a 13-year recession that has spurred an exodus of its residents and bankrupted its government. About 4 percent of Puerto Rico’s population left in 2018, and the number of people living on the island has fallen by 15 percent since 2008, according to a Pew Research Center report released earlier this week.

A 2019 study by the University of Michigan found that the federal response was both faster and more generous after hurricanes struck Florida and Texas than it was for Puerto Rico. Congress also let expire emergency food stamp aid for Puerto Rico in March, causing reductions in critical federal help for more than 1 million island residents.

“While regrettable, and anyone who committed wrongdoing should pay to the full extent of the law, this does not in any way, shape or form change the real need tens of thousands of people in Puerto Rico have for disaster aid,” de Jesús said of the arrests. “Corruption has also happened in other jurisdictions, and that never slowed down aid. This should not be any different.”

The Trump administration has said the island received more money than Texas, Florida or California for natural disasters in those states. It has also said it should not waste taxpayer money due to the island’s long-standing problems.

“The Trump Administration will not put taxpayers on the hook to correct a decades-old spending crisis that has left the island with deep-rooted economic problems,” White House spokesman Judd P. Deere said in a statement earlier this year.

Josh Dawsey contributed to this report.