SAN DIEGO -- The U.S. government said John Carman conspired to kidnap an American in Mexico.

Carman has been sitting in a federal facility in downtown San Diego, awaiting his day in court.

Now, that day has arrived.

On one side, former U.S. Customs agent Carman is described by some as a whistleblower.

Carman claimed he was framed by the government to keep him quiet.

However, the government said it has a confidential informant and FBI wiretaps that prove he is a criminal.

Carman's family describes him as a man of integrity.

Carman devoted 25 years of his life to law enforcement, the last decade with U.S. Customs.

"My brother is an American hero. He's worked hard at when he worked for Customs," said Carman's sister Cindy Carman.

John Carman is accused of conspiring to kidnap an American citizen in Mexico, a charge the federal government backs up with wiretaps, e-mails and other evidence.

The 10News I-Team obtained a copy of the indictment and according to the documents, the government's case against Carman included a confidential informant who was convicted of illegally staying in the U.S. and for making false statements to law enforcement officers.

Cindy Carman said she believed there was something dirty going on.

According to colleagues, John Carman had a track record of blowing the whistle on corruption within federal law enforcement.

Cindy Carman claimed her brother's exposure of corruption years ago led to retaliation and his eventual dismissal from U.S. Customs.

"It makes me feel they're trumped up charges as a vendetta," said Cindy Carman.

Supporters of John Carman claimed that as a private investigator, he was working on a custody case across the U.S.-Mexico border when he ran into trouble.

Former U.S. Customs agent Darlene Fitzgerald said, "It's absurd that he's in jail. In my humble opinion, he's a political prisoner."

Fitzgerald is a whistleblower advocate and author of the book "Bordergate." She said the book exposes corruption within the federal government.

She said she stands behind Carman and felt that he was a victim of retaliation.

"I don't think it's a coincidence that he was arrested right before he was supposed to testify in Congress," said Fitzgerald.

Fitzgerald said she and Carman were due to testify about several alleged misdeeds and dysfunction within federal law enforcement.

She claimed Carman's testimony would have embarrassed many high-level government officials.

"He was going to talk about more specific issues to his corruption …with over-flight exemptions, port directors who were on the take. He had evidence to that," said Fitzgerald. "Because he spoke out and he has the integrity to do that, he suffered for it."