(CNN) Before US immigration authorities detained him and took his son, the Honduran migrant said he spent three days in the hands of armed men who identified themselves as members of the Gulf Cartel.
Christian, who did not want his full name used, said he was traveling to the US border with his 7-year-old last month when the men stopped a bus full of migrants in the northeastern Mexican state of Tamaulipas. The demanded $300 from each family.
"They told us if we didn't pay that they were going to kill us," recalled Christian, who said he was freed three days later after relatives wired money to his captors.
"There were 30 of us. There was another building next to where we were being held and they said there were even more people there."
President Donald Trump has said that he wants immigration policy that secures the border. But his aggressive policy has instead resulted in organized crime groups preying on droves of desperate asylum seekers who have been turned away by US authorities, according to people familiar with the smuggling operations.
Experts said the administration's now-reversed policy of prosecuting parents who cross the border illegally -- thus separating children from their families -- and the elimination of domestic violence and gang violence as grounds for asylum is having another result: Further strengthening ties between human smugglers, other organized crime groups and corrupt local law enforcement along the border.
"Ironically, these policies that claim to be trying to clamp down and secure the border and stop smuggling and stop traffickers... actually empower the traffickers, the cartels, the smugglers," says Michelle Brané, director of the Migrant Rights and Justice program at the Women's Refugee Commission.
Christian and his son eventually reached the US, where immigration authorities detained them and separated him from his son in mid June. He said he was held at the Port Isabel Detention Center in Texas, where he claims he went nearly two weeks without word of his son's whereabouts. After a month in detention, he was released and reunited with the boy. He has a court date next month.
But the trauma of the journey to America started days before he crossed the Rio Grande.
Christian said he had fled the violence of his homeland but was then detained by men who said they were part of the Gulf Cartel, which has an extensive transnational network in Central and South America. They repeatedly threatened the more than two dozen migrants who slept on the floor of a house in Mexico. The migrants came from El Salvador, Honduras and Guatemala. The youngest was about 12 months old.
"My child was with me the whole time," Christian said. "He would just bury his face into me for protection."
While organized crime groups along the border have long preyed on US-bound migrants, experts said the administration's immigration policy has increased the desperation of those migrants, as well as the demand for smugglers and the cost for their services.
That desperation increased after nearly 3,000 children were separated from their parents as a result of the White House's now-reversed zero tolerance immigration policy, according to experts and advocates.
The cost for clandestine passage into the US for migrants from Central America has soared from $6,000 to $8,000 a couple of years ago to about $12,000 today, according to Guadalupe Correa-Cabrera, a professor at George Mason University and an expert on organized crime and immigration.
"An unforeseen consequence of this (immigration crackdown) is the strengthening of criminal groups that are very organized and smugglers that are transnational and have connections with different groups," she said. "You create these monsters in reality with your own policies."
The money collected from the migrants helps grease sophisticated smuggling networks involving drivers, guides, stash houses, corrupt local police and people with links to criminal organizations, including the drug cartels, she said.
"The connections between organized crime and migrant smugglers are becoming tighter," Correa-Cabrera said.
"They are lords of the routes, of these dangerous journeys. They manage because they have the connections with local police, the cartels and other criminal groups."
Juan Francisco Loureiro said he came across 15 Central American migrants sitting together earlier this month in the food court of a shopping center in the Mexican border city of Nogales.
"I asked if they needed anything," said Loureiro, who runs a small migrant shelter a couple of miles south of the border from Nogales' sister city in Arizona.
A migrant said they were waiting for the smuggler who delivered them there. The guide told them to stay inside to avoid the US Border Patrol agents, according to Loureiro.
"You're still in Mexico," Loureiro told them.
"They told us we were in the United States," the migrant said.
They refused to believe him. Loureiro said he offered to take them to the San Juan Bosco shelter, which he has run for more than 30 years. They insisted on waiting.
In Nogales, Loureiro said human traffickers have been capitalizing on Washington's stricter enforcement actions since a caravan of Central American migrants seeking asylum arrived at the US-Mexico border in May.
"They see the desperation of people and they're taking advantage," he said. "The human smuggling business has taken off since the caravan. The smugglers prefer migrants with family in the US. They know family members will respond when they demand money."
Loureiro said migrants at the shelter have told him smugglers have been going around seeking families with relatives north of the border.
"We see people who waited up to 15 or 20 days trying to get across the bridge legally and then we don't see them again," he said. "Many eventually connect with smugglers who prey on their desperation."
The administration's new policy of rejecting asylum claims based on fears of gang and domestic violence will result in potentially thousands of people being turned away before they can plead their cases in court.
Immigration lawyers and advocates said turning away traumatized immigrants puts their lives at risk immediately upon their return home.
"More people are going to be assassinated, more people are going to suffer from domestic violence, more people are going to die," said Carlos Garcia, an immigration attorney in McAllen, Texas. "That's the reality. When I go and talk to them at the detention center ... they look at me and they tell me, 'I can't go back.'"
More and more migrants, especially women with young children, will turn to smugglers, according to experts.
"More powerful criminal groups means more corruption, more instability and -- contrary to the Trump administration's wishes -- more migration," Steven Dudley, co-director of InSight Crime, a foundation that studies organized crime in the Americas, wrote in an analysis last month.
Brané, director of the Migrant Rights and Justice program at the Women's Refugee Commission, said the desperation of migrants makes them more vulnerable to exploitation by criminal groups.
"We see migrants who don't have the money to pay these higher prices but are that much more desperate, and so then you start seeing a market for traffickers saying you can pay me off when we get to the other side, and that's when the smuggling turns into trafficking," she said.