A US teenager who was detained by border agents for nearly a month, has detailed bleak conditions during his stay, saying: “They were not treating us humanely.”

Francisco Galicia, who was born in Texas, was detained at a customs and border agency (CBP) checkpoint in Falfurrias, Texas on June 27 while travelling with his brother Marlon, a 17-year-old who was born in Mexico, who was also detained. After two days of detention, Marlon signed a voluntary deportation form and was released to his grandmother. Francisco, who was finally released this week, said he almost did the same thing.

“It was inhumane how they treated us,” he told the Dallas Morning News. “It got to the point where I was ready to sign a deportation paper just to not be suffering there anymore. I just needed to get out of there.”

Francisco, 18, lost 26 pounds during the 23 days he was detained at the CBP facility due to lack of food. He was not allowed to shower for the duration of his stay, but was given a shower once he was moved to an immigration enforcement agency (ICE) facility.

“It was to clean up but the dirt, but you couldn’t get rid of it because so much time had passed since we showered,” he said.

He and 60 other men were held in an overcrowded holding area where they slept on the floor; some were forced to sleep on the restroom area’s floor. They were given only aluminium foil blankets.

Francisco said ticks bit some of the men. Some were also “very sick”, he said, but afraid to ask for a doctor, since CBP officers told them their stay would start over if they did.

“It’s one thing to see these conditions on TV and in the news,” he said. “It’s another to go through them.”

The horrifying saga began when officers at the Falfurrias checkpoint questioned his citizenship status. The teenager also had a Mexican tourist visa his mother had obtained for him when he was a minor and she feared she would not be able to legally travel across the border with him.

But Francisco says the officers sounded the validity of his identification documents even before knowing that.

'Dangerous' overcrowding of migrants in US border facilities Show all 6 1 /6 'Dangerous' overcrowding of migrants in US border facilities 'Dangerous' overcrowding of migrants in US border facilities Photos of detained migrants crowded into cells at the US border - with one holding up a sign reading simply "help" - have been released as part of a new report warning of "dangerous" overcrowding. The memo was sent to the Department of Homeland Security by its Inspector General, containing photos taken at border facilities in the Rio Grande Valley over a week in June DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Eighty-eight adult males held in a cell with a maximum capacity of 41, some signalling prolonged detention to OIG Staff on June 12 DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Overcrowding of families observed by OIG on June 11, at a border patrol facility in Weslaco, Texas DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Migrant families overcrowding a border patrol facility on June 11 in McAllen, Texas DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Fifty-one adult females held in a cell designated for male juveniles with a capacity for 40 at Border Patrol’s Fort Brown Station DHS/OIG 'Dangerous' overcrowding of migrants in US border facilities Migrant families overcrowding a border patrol facility on June 11 in McAllen, Texas DHS/OIG

“I told them we had rights and asked to make a phone call. But they told us, ‘You don’t have rights to anything,’” he told CNN. “They didn’t believe me. I kept telling them over and over, and they kept saying my documents were fake, and they were going to deport me.They threatened me with charges – charges about falsifying documents. Felonies. They kept asking how it was possible for me to not know where I was from.

“Powerless. That’s how I felt,” he continued. “How with all this proof that I was giving them could they hold me?”

Now, he wants to use his experience to shed light on the sordid conditions enacted by the Trump administration in the camps.

“Right now, I’m in a place where I can help those who are still in there – so people can see how they’re treated, and change the way they’re treated,” he said. “I am the eyes and ears of what’s happening in there. I can talk. They can’t do what I’m doing.”