An Indian immigrant living in Lake Mary, Florida, was arrested at Orlando International Airport on Friday on charges he threatened to kill a California congressman, court documents say.

When FBI agents met Hari Pinto at the airport, he allegedly admitted to making threatening phone calls to the congressman, who is only identified as “Congressman A,” an arrest affidavit said.

“Pinto explained that he threatened to kill Congressman A because he was frustrated by the voices in his head and frustrated by not getting any help in his previous calls,” the affidavit said. “Pinto went on to explain that he often hears voices in his head that tell him to do things and that he listens to the voices.”

The congressman’s staff members told investigators they have received numerous calls from Pinto, starting on Jan. 5.

According to court documents, Pinto asked to speak to the congressman directly, saying his brother was having issues and being harassed in the U.S.

The next morning, the staffer was shocked by a voicemail that had been left at the congressman’s Washington D.C. office.

“The caller stated that Congressman A was a terrorist and that the caller would ‘kill’ Congressman A,” the affidavit said. “The voicemail ended when the caller stated, ‘Be careful.’”

On Jan. 11, another call attributed to Pinto was received at the congressman’s office, investigators said.

“The caller stated that Congressman A’s office was a threat to him and continued to express his anger at Americans all over the world,” the affidavit said.

The FBI was able to trace the cellphone that was used to make the calls to Pinto’s nephew, who told investigators that his uncle was a software engineer who was in the U.S. on a green card.

“(The nephew) explained that his maternal aunt is married to Pinto ... (and) lives in India and raises her and Pinto’s child while Pinto works in the United States to support them,” the affidavit said.

Pinto told investigators that he had been in India when he made the alleged calls, officials said.

He is facing charges of transmitted in foreign commerce, via interstate communication, a threat to injure another person.