Duncan Hunter on Greta Van Susteren's show, October 7, 2014

The Department of Homeland Security strongly challenged Rep. Duncan Hunter's assertion on October 7 that ISIL fighters have been captured while trying to enter Texas across the border with Mexico.

Department of Homeland Security spokeswoman Marsha Catron said, in a written statement, that: "The suggestion that individuals who have ties to ISIL have been apprehended at the Southwest border is categorically false, and not supported by any credible intelligence or the facts on the ground. DHS continues to have no credible intelligence to suggest terrorist organizations are actively plotting to cross the southwest border."

On Tuesday's Fox News program, Hunter told Greta Van Susteren, "I know that at least 10 ISIS fighters have been caught coming across the Mexican border in Texas."

Hunter said that he learned this from sources in the Border Patrol, which captured the Islamic militant fighters, then added, “You know there's going to be dozens more that did not get caught by the Border Patrol."

Inquiries to the Border Patrol were directed to the parent agency, the Department of Homeland Security, which strongly denied Hunter's statements. A spokesman for the National Border Patrol Council, the union for about 17,000 Border Patrol agents, said they hadn't heard about the alleged incidents. He spoke only with the agreement he not be named.

No one had reported such detentions to the union and no bulletins to be on the lookout for ISIS fighters have gone out to patrol agents, he said, noting they had antiterrorism training as part of their training and refresher courses.

Hunter spokesman Joe Kasper said that Hunter maintains that what he said is true.

"A high level source informed the congressman,” said Kasper. “It was also said that [the Department of Homeland Security] is actively discouraging any talk of IS on the border. The congressman was conveying what he knows — and what he was told."

Hunter has been a strong proponent for securing the border, advocating for stronger enforcement and more spending to build fences along the 2000-mile border with Mexico. A bill he introduced in 2011 remains stalled in the house Subcommittee on Border and Maritime Infrastructure.

Hunter has tangled with the Department of Homeland Security before, including when he released previously unreported information about a number of incursions by Mexican police and military into the United States — information he had to file a Freedom of Information Act request to obtain.

"It makes sense that the left hand of DHS doesn't know what the right hand is doing — it's been that way for a long time and we don't expect that to change," Kasper said.