Federal agents escort former Puerto Rico Health Insurance Administration head Ángela Ávila-Marrero who was arrested in San Juan, Puerto Rico, on Wednesday as part of a corruption investigation that resulted in an indictment against six defendants.

Carlos Giusti/AP

U.S. authorities have unsealed a corruption indictment against two former top officials in Puerto Rico for directing some $15.5 million in contracts to favored businesses, allegedly edging out other firms for the lucrative government work despite allegations of being unqualified.

The two former Puerto Rico leaders — Julia Keleher, who was the secretary of the island's department of education before stepping down in April and Ángela Ávila-Marrero, who led Puerto Rico's Health Insurance Administration until last month — were arrested by FBI agents on Wednesday.

Prosecutors wrote in the indictment that the conspiracy involved the two former public officials handing four associates who had an inside track to contracts.

Once secured, authorities say the contractors benefited by paying "unauthorized commissions" to other individuals to lobby government for more contracts, a dynamic authorities described as "a corrupt bidding process."

At a press conference in San Juan, U.S. Attorney for Puerto Rico, Rosa Emilia Rodríguez-Vélez elaborated.

"Both Keleher and Avila-Marrero took advantage of their privileged positions as agency chiefs. They defrauded the U.S. and Puerto Rican governments," Rodriguez said.

Federal authorities also arrested and charged Glenda Ponce-Mendoza and Mayra Ponce-Mendoza, who are sisters who worked as education consultants; Fernando Scherrer Caillet, an executive at the auditing firm B.D.O.; and consultant Alberto Velázquez Piñol. The 32-count indictment accuses the defendants of charges including wire fraud, theft and money laundering.

The charges related to steering lucrative government contracts to business friends come at a politically sensitive time for the island's government, which has been trying to project a polished and competent image of themselves to Congress as island leadership expect to receive billions of dollars in recovery aid to help rebuild after Hurricane Maria, reports NPR's Adrian Florido.