The end of the nine-day official mourning period of Fidel Castro's death means life is back to normal for most Cubans — except for Danilo Maldonado, who languishes in a Cuban prison.

His crime? On the day of Castro's death, the 33-year-old dissident graffiti artist known as "El Sexto" marked the occasion by spray painting his street name on a Havana hotel wall, along with the cheeky message "Se fue" (He's gone).

It didn't go over well with authorities.

Maldonado's mother, Maria Victoria Machado, said she was told by her son's neighbours that early Saturday morning, police broke into his apartment, grabbed him and violently dragged him down the stairs into an awaiting patrol car, all while punching him in the stomach and torso.

When Machado went to visit her son in jail, she said he told her the beatings had continued there.

He has yet to be charged, she said, but authorities told her he was arrested for "damage to public property." On her last visit to the detention centre El Vivac, where until Wednesday Maldonado was being held, Machado was told he could be there for another 60 days.

"They are furious," Machado said. "They are really upset because of what Danilo did."

el sexto mom

Maria Victoria Machado said she was told by her son's neighbours that early Saturday morning, police broke into his apartment, grabbed him and violently dragged him down the stairs into an awaiting patrol car. (Mark Gollom/CBC)

A spokesman for the detention centre told CBC News that Maldonado is "being held legally and is under investigation."

"We don't torture anyone here. All legal. We don't beat anyone up or torture," he said.

The day after CBC contacted El Vivac, Machado said she received a call from a fellow inmate at the centre, telling her that her son is being denied his daily phone privileges. On Wednesday, Maldonado had been moved to the Valle Grande prison, according to his girlfriend Alexandra Martinez, who lives in Miami.

Meanwhile, Amnesty International has declared Maldonado a "prisoner of conscience" and is calling for his immediate release.

Machado wants people to know about her son's incarceration. Before an interview with CBC News, she changed her T-shirt to one that bears the words "Free El Sexto."

"This is a kind of way to protect him and make pressure," she said, sitting in the Havana home of her son's friends — political activists who know all too well the risks of antagonizing the Cuban government.

Past imprisonment

Maldonado's street name is an ironic twist on the Cuban Five — five Cuban spies who were arrested in the U.S. for espionage and other illegal activities. They have been deemed heroes by the Cuban government, and Maldonado, tongue-in-cheek, declared himself the sixth member.

But it's that ironic sense of humour that has landed him in trouble before. He was jailed for 10 months in 2014 after he painted the names Fidel and Raul on two live pigs, intending to release them as part of an art show.

His mother said she fully supports the actions of her son — who was last year awarded the Václav Havel International Prize for Creative Dissent — but she is concerned about his fate. 

"What are they going to do — because they've been mistreating him inside of the police station."

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A man walks next to graffiti reading 'Long live Fidel' and 'Long live Raul' in Havana. (Yamil Lage/AFP/Getty Images)

Maldonado has refused to eat the food he has been receiving since detained, concerned it was being laced with drugs to "quiet him down." When in jail, they allowed his mother to bring him some snacks — a drink and a small piece of fried chicken. However, authorities at the detention centre have told her they will only permit her to visit once a week.

'This kind of totalitarian regime doesn't like the humour.' - Antonio Rodiles, friend of 'El Sexto'

When asked whether she believes Maldonado should face any punishment for his actions, Machado said the Cuban government has no problem with graffiti, even on private homes, if it expresses support for Castro and the revolution.

"Why can't he put [up] one against the regime? If they want to do something, they can give him a fine or a ticket. But not put him in the police station to beat him."

Did video play a role?

It's possible the government was irked by more than his graffiti on the hotel wall.

After Castro's death, Maldonado also took to the street using Facebook Live, streaming a video of himself asking people what they thought about the leader's passing. His mother said he did it in front of the international press centre; she thinks that police initially let him be, not wanting to attract attention of the hordes of foreign media.

"They have been upset with Danilo from the beginning," said Antonio Rodiles, a friend of Maldonado and a well-known political activist in Cuba. "Because this kind of totalitarian regime doesn't like the humour and he's making fun of these people. They are not accustomed to that."

Rodiles, a vocal critic of the government, said he himself has run afoul of the Cuban authorities and has also been arrested and assaulted. 

Cuban political activist

Antonio Rodiles, a vocal critic of the Cuban government, said this picture of himself was taken shortly after he was beaten by a group of men who didn't want him to attend a protest rally. (Antonio Rodiles)

He showed CBC a picture of injuries he says he sustained a year ago, when he said he was beaten by a group of men who didn't want him attending a peaceful protest rally. The picture shows him with a bandaged nose and bloodied shirt.

"They broke my nose, my ear drum," he said. 

Rodiles said the authorities are always watching his activities and have bugged his home and placed cameras out front.

​"We are accustomed to that, unfortunately. That's why we want a different country."

Maldonado wants the same thing, said his girlfriend Alexandra Martinez.

"[He] wants his country to be free and be to able to speak freely," she said.

"He didn't harm anyone … just merely spoke his mind. And unfortunately the Cuban government has no tolerance for that."