Lawyers who visit their clients in the Altiplano, Mexico’s highest-security prison, say they must leave behind their wallets, pens, tie clips, shoelaces. They complain that guards check inside the men’s underwear and women must take off their bras.

Those in solitary confinement, such as the prison’s most famous inmate, drug lord Joaquin “El Chapo” Guzman, are under constant surveillance and receive just one hour of daily caged-in recreational time, according to those familiar with the prison.

So the news in July in the Mexican magazine Proceso that Guzman had organized nearly 1,000 prisoners to hold a five-day hunger strike to protest the prison’s poor hygiene, medical care and food seemed curious. Not just that the world’s most fearsome drug lord was now apparently a human rights crusader but that he had the freedom of movement and communication inside the prison to pull it off.

The prison, amid rolling farmland west of Mexico City, is tough to get inside, and the Mexican government denied requests to visit or speak with those who run it. Mexican officials confirmed that the mid-July hunger strike took place but denied that Guzman, or the other famous drug lord apparently involved, Edgar Valdez Villarreal, a.k.a. “La Barbie,” participated.

“There is no way that any one of them could participate because they are totally isolated,” one Mexican official said.

The official, who was granted anonymity because he was not authorized to speak publicly about the issue, said the strike lasted “some hours” and involved about 100 people. “There were never 1,000, never.”

That Guzman is in prison is a victory for the Mexican government. He had escaped from incarceration once before, in 2001, and his legend grew as he led the Sinaloa Cartel, the multibillion-dollar drug trafficking operation. In February, a team of Mexican marine commandos burst into his room in a beach condo and snatched him. After being briefly marched before a news conference in Mexico City, Guzman was taken to the Altiplano and out of public view. The Mexican government plans to pursue criminal charges against him before considering extradition to the United States, where he has also been indicted.

According to lawyers, former inmates, relatives and others, the Altiplano is hard living. Some people complained about dirty cells, not enough blankets, a lack of medicine. “There is mold, they get sick, it’s cold, they don’t take care of them,” said a lawyer, who declined to give his name to preserve his access to the prison. They also said most prisoners, except for those in solitary, have plenty of opportunity to interact with each other.

A former inmate who spent nearly five years inside the Altiplano said that the prison has eight modules, each divided into four sections. When prisoners go out onto the patio for recreation hour, they’re only supposed to talk to other inmates from their section, he said. He slept in a bunk bed, with two prisoners per room, he said, and toilets were in public view. But he found the medical care sufficient and was treated for his hypertension.

“They never ran out of medicine,” he said. When he was imprisoned from 2008 to 2012, he said, there were periodic hunger strikes over different issues, including one seeking larger television screens.

After the most recent protest over food quality, medical care and hygiene, the Mexican official said, the “demands were satisfied and the protests were reduced.” He did not specify how the demands were satisfied.

Some inmates received new shoes, according to the sister of a prisoner. A subsequent Proceso article described the strike as a “triumph” for Guzman and Valdez.

Those familiar with the prison said Guzman does apparently get some preferential treatment: While other prisoners are forced to shave, he’s been allowed to keep his mustache.