(NewsNation) — The flow of illegal drugs and guns has become a multibillion-dollar business along the southern border, and there are growing concerns federal agents could be enticed to help the cartels.

In 2020, The Intercept reported that the former head of U.S. Customs and Border Protection’s (CBP) internal affairs believed between 5 and 10 percent of CBP’s workforce of roughly 50,000 was either actively or formerly engaged in some form of corruption.

As Mexican cartels continue to expand their business dealings — and morale continues to plummet within CBP — there is concern that the temptation could breed more corruption among officers and agents on the front lines.

Retired Border Patrol Sector Chief Victor Manjarrez says there were cases during his career where U.S. Customs and Border Protection (CBP) officers and Border Patrol agents supported cartels by turning a blind eye.

“It was the action of taking no action,” said Manjarrez. Those favors put entire families at risk, he said.

J.J. Carrell retired in 2021 after being with Border Patrol for 24 years and saw how agents could get roped into helping the cartels.

“When you do it once, the cartel owns you,” he said. “You’re gonna shut up because (they’ve) got you on camera and (they’re) going to turn you in.”

For Carrell, the deep-seated corruption that the former head of CBP’s internal affairs believed existed in the agency, was not a reality he saw on the ground. He only knew of three or four “dirty agents” out of the thousands he worked with and supervised.

When it comes to betrayal, there’s little sympathy from within the agency.

“If you can’t take it and you think it’s that abysmal, which it is, then you need to man up and quit,” Carrell said. “You don’t smuggle. You don’t become part of the problem. You try your hardest to be the solution.”

From fiscal year 2019 to 2021, Border Patrol agents on the front lines accounted for 39% of the more than 26,000 CBP misconduct investigations.

Attorney David Zugman has represented some of the Border Patrol agents in the field, as well as CBP officers at ports, who have dabbled in deceit.

“It starts with little things that are not being enforced, that turn into big things that are not being enforced,” said Zugman. “And it’s a very difficult problem to get a handle on.”

Zugman represented Lorne Leslie “Hammer” Jones, who in 2014 was sentenced to 7 1/2 years in custody for selling his badge to human smuggling groups and Mexican drug cartels.

Historically, CBP has attracted twice as many dishonest recruits as other law enforcement entities.

According to a Committee on Homeland Security and Governmental Affairs hearing in 2019, about 65% of all applicants fail the agency’s polygraph examination, while the American Polygraph Association says a 30% failure rate is normal for law enforcement hiring. The FBI, for example, has a failure rate of less than 35%.

“What better time to be a dirty agent than right now when there’s no one watching the border?” said Carrell. “Let’s just be honest, let’s just say it as it is.”

When it comes to national loyalty, it’s not just a small percentage of agents turning their backs on the U.S.

The vast majority of human smugglers arrested along the southern border are U.S. citizens and CBP finds the majority of people bringing drugs through the ports of entry are also U.S. citizens.