Updated

Joshua Holt, the 24-year-old American jailed in Venezuela on weapon charges since June 30, is being submitted to treatment that his lawyer says is “cruel, inhumane and degrading.”

Attorney Jeanette Prieto told Fox News Latino she is preparing a human rights violation complaint.

“As punishment, he was forced to take off his clothes off and do squats in a hallway,” she said, adding that the reason for that punishment was never explained. “That is something that affects his dignity and his integrity. The inmates, regardless of their nationality, should be treated with respect.”

“It’s a cruel, inhumane and degrading treatment,” she added.

Prieto also said that the prison guards had violated Holt's Mormon faith by forcing him to remove his undergarments, which are similar to holy vestments worn in other religious faiths, such as a Catholic nun's habit or a Muslim skull cap.

Holt was scheduled to have a hearing Tuesday, but it was canceled at the last minute, as often happens in Venezuela's flawed judicial system. The hearing was canceled because the judge failed to show up. It was the second time the hearing was postponed for that reason.

Holt's mother was distraught when reached by phone Tuesday in Utah about yet another canceled hearing and the news her son had been treated poorly.

“His health is suffering. He is peeing blood and [has] diarrhea,” Moon Holt told FNL. She said she's doing her best to stay strong.

"It infuriates me. They're not treating him like he should be treated," she told the Associated Press. "Obviously, they're not giving him due process. At this point, I'm not sure where to go or what to do but pick back up and start fighting again."

Holt was arrested on June 30 along with his Venezuelan wife of five days, Thamara Caleño Candelo, whom he met online while looking for Spanish-speaking Mormons to help him improve his Spanish.

Venezuelan authorities contend Holt was using his wife's apartment in Caracas to stockpile weapons and have suggested his case is linked to other attempts by the U.S. to undermine President Nicolás Maduro's socialist rule amid deep economic and political turbulence.

Holt and his wife insist the weapons were planted.

U.S. Secretary of State John Kerry raised concerns about Holt's case last month during a meeting with President Maduro.

Sen. Orrin Hatch of Utah said in a statement Tuesday that he was disappointed by reports of Holt's mistreatment. He said he'll continue to work with Kerry and Vice President Joe Biden to demand answers. He commended Josh for "his tremendous courage throughout this terrible situation."

Rep. Mia Love of Utah, who is also working on Holt's behalf, said in a statement that she was outraged and heartbroken. The latest cancellation of a hearing "represents a lack of respect for human dignity and civil rights," Love said.

With reporting by The Associated Press.