A 30-year Immigration and Naturalization Service border patrol veteran has been fired, most likely because he wanted to testify before Congress about his experiences, said a Republican lawmaker.

The agent, who has asked not to be identified, was given his walking papers on Oct. 10 and will be out of a job 30 days from that date, according to Rep. Tom Tancredo, R-Colo.

Tancredo said Wednesday that the agent received the notice after he was asked to testify  before the House's Immigration Reform Caucus, a 30-member group which Tancredo chairs.

Tancredo said the INS at first approved of the agent's testifying but with restrictions. Later, Tancredo's office was contacted by the Justice Department and told the agent could not testify at all, the congressman said.

The INS has called Tancredo’s assertions "not credible."

Tancredo has proposed the creation of a new border patrol security agency to replace the INS in order to stem the flow of illegal aliens into the country at the north and south borders.

Tancredo, an immigration hawk, has said the INS has a conflict of interest in trying to stem illegal immigration while facilitating legal immigration. He said it has a serious enforcement problem, considering that nearly 300,000 individuals ordered deported from the United States are not accounted for by the INS.

Tancredo said that the agent had a "firsthand account on the inner workings of the agency," and was a threat to its livelihood.

Tancredo "had hoped to have a hearing, not a press conference," Wednesday but said that the INS "whistleblower" had not been released to testify.

"I believe Governor Ridge when he says this is a time for candor and disclosure, but it appears INS is not getting the message," Tancredo said.

"It is clear that if we are going to secure our borders and protect our country then we must end INS as we know it and form a new agency that has the ability and the will to enforce the law," he added.

The congressman has been on the forefront of a movement that is calling for increased vigilance at the borders in the wake of the attacks on the World Trade Center and the Pentagon on Sept. 11. Earlier this month, Tancredo said he was designing a bill that would place a six-month moratorium on immigration so that the current system could be improved.

When asked if the congressman had planned to look into the agent's termination, spokesman Greg Meyer said, "We are obviously very interested in providing whatever assistance we can to him. Right now, I couldn’t give you a point of action to take."

Fox News' Kelley Beaucar contributed to this report.