YUMA, Ariz. — Congressional Republicans who toured part of the southern border this week saw firsthand the number of families and children arriving.

But the House lawmakers were shocked at the idea that smugglers recycle children across the border.

“I think the entire delegation was shocked,” said Luke Ball, press secretary for Rep. Matt Gaetz, R-Fla.

The Washington Examiner was riding along with Reps. John Joyce of Pennsylvania, Pete Stauber of Minnesota, Dusty Johnson of South Dakota, Andy Biggs of Arizona, and Gaetz Tuesday night when officials leading the tour pointed to a group of more than 40 people who had just crossed through the Colorado River south of the Morelos Dam and surrendered to Border Patrol agents less than a quarter-mile into the U.S.

“Right now, they’re getting their biographical information: name, first name, last name, date of birth, nationality. Right now, they may ask them where they’re going — how many people, if it was a family unit, were they by themselves, were they minors?” an agent, who spoke on background, told the group of lawmakers.

“Every one has a kid, at least one. Every one has a kid,” one congressman reacted at the scene.

A Border Patrol agent speaking to lawmakers said agents in the Yuma sector, which has seen the third-highest family apprehensions of all nine sectors this year, said some children are being sent back to Central America after making it to the U.S. The agent said children are being “rented out.”

“They know that’s their ticket in,” one lawmaker said.

The group saw another 35 people taken into custody during a ride-along Wednesday.

“They just walked up and surrendered themselves. They did not try to run. They did not try to get away because what we learned last night … is that if they come in as a family unit, they will be released probably less than two days, and they’re not allowed to hold them for a certain period of time, so essentially they are presenting themselves at the border and saying they are a family unit,” Ball said.

Joyce wrote in an email that the adults used children as "fast passes to permanent entry."

A Border Patrol agent on the tour said the agency has begun documenting and referring for prosecution individuals who recycle children who traveled from Central America to the U.S. then were sent back to Central America or Mexico so that an unrelated adult could take them on that same journey and claim them as his or her child.

Doing so allows a person who has illegally crossed into the U.S. to apply for asylum and not be held in custody more than 20 days due to a 2015 court ruling that mandates families not be held more than that amount of time.

Because agents do not take fingerprints or other biometric information from children 14 years old or younger, they cannot verify if a child being taken into custody is arriving for the first time or is related to the adult bringing them, the agent said.

Justin Kallinger, spokesman for the Yuma sector, said 99% of all migrants they take into custody paid thousands to be smuggled to the U.S. and did not travel as part of a caravan. Kallinger said because adults being smuggled want to avoid deportation and prosecution, they are relying on a “new advantageous technique” by recycling children.

“They can utilize loopholes in the immigration law. These children don’t know. They take these one month trips — traversing through horrible, horrible conditions multiple times,” said Kallinger. “Certain children are being recycled, 4-, 8-, 10-year-old children. They come with false documents from adults.”

Data provided by Border Patrol’s Yuma sector indicates only a small percent of families arriving in Yuma are committing fraud.

Of the nearly 25,000 people arrested in Yuma in the past six months who claimed to be part of a family unit, nearly 600 were not related to one another and 100 of those cases were referred for prosecution, according to sector data provided Friday.

“We have prosecuted as many as we can. We run into issues with evidence, intent, time in custody once it is found to be a fraudulent family unit are just a few of the barriers we face right now,” Kallinger said in a follow-up email.

Sen. Martha McSally, R-Ariz., confirmed the "recycling" of children to reporters during a press conference in Yuma Wednesday.

"This is a humanitarian crisis. Incentivizing individuals to then send a child on this dangerous journey and then send them back again and have them take the journey again, that is traumatizing this children," McSally said. "One of the challenges I understand we’re looking more into it is the collection of those biographical and photograph and biometric information of the younger individuals unless they have consent."

Joyce said he will return to Washington after the Easter recess and focus on changes to asylum policy. Ball, Gaetz's spokesman, agreed with that approach.

“I think that right now we have a gap where folks are able to come over because there's no physical barrier. There are changes needed in the law,” said Ball. “But we first have to plug the dyke.”