In the days before the Trump administration deported hundreds of Venezuelan immigrants to a notorious prison in El Salvador, the president of that country demanded something for himself: the return of nine MS-13 gang leaders in U.S. custody.

Secretary of State Marco Rubio, in a March 13 phone call with Salvadoran President Nayib Bukele, promised the request would be fulfilled, according to officials familiar with the conversation. But there was one obstacle: Some of the MS-13 members Bukele wanted were “informants” under the protection of the U.S. government the Trump administration’s willingness to renege on secret arrangements made with informants who had aided U.S. investigations has not been previously reported. “The deal is a deep betrayal of U.S. law enforcement, whose agents risked their lives to apprehend the gang members,” said Douglas Farah, a U.S. contractor who worked with federal officials to investigate and help dismantle the MS-13 gang.