A crucified Ronald McDonald clown, prayer mats adorned with stilettos and sketches by former Guantanamo prisoners take pride of place at a new museum in Spain devoted to previously censored art.

The private Museum of Forbidden Art, which opened to the public in Barcelona on Thursday, features 42 works from around the world that have been denounced, attacked or removed from exhibition.

Works by artists such as Spanish master Francisco de Goya, US cultural icon Andy Warhol and Chinese artist and activist Ai Weiwei are spread over two floors.

The objects are part of a collection of 200 such works belonging to Tatxo Benet, a Catalan businessman.

While they push boundaries and often sparked controversy, Benet said this was not enough to be included in the museum, located in the centre of the Catalan capital, one of the world's most visited cities.

"We don't collect or show scandalous or controversial works in the museum. We show works in the museum that have been censored, assaulted, violated, banned," he told AFP.

"Works that have a history behind them, without that history they wouldn't be here," he added.

'Always have a place'

Many works deal with religion, such as Finnish artist Jani Leinonen's "McJesus" of a Ronald McDonald sculpture crucified to a wooden cross, which was withdrawn from a museum in Israel.

The museum also showcases a photograph of a crucifix submerged in the urine of New York artist Andres Serrano, which was vandalised during an exhibition in France and sparked an uproar when first shown in the United States in 1989.

Another highlight is a work by French-Algerian artist Zoulikha Bouabdellah featuring 30 Muslim prayer mats, each adorned with a pair of sequinned stilettos, which was pulled from an exhibition in France in 2015 following complaints from a Muslim group.

Benet, one of the founders of Spanish multimedia group Mediapro, said he started building his collection in 2018 when he bought an installation called "Political Prisoners in Contemporary Spain".

It consisted of black-and-white photos with pixellated faces of people who had broken the law, among them Catalan separatist leaders who faced legal action over a failed 2017 secession bid.

The work, by Spanish artist Santiago Sierra, was pulled from a Madrid art fair just two hours after Benet bought it. It is now on display at another museum in the Catalan city of Lleida.

The museum also displays paintings and sketches by former prisoners at the US naval base at Guantanamo Bay in Cuba, including one of the Statue of Liberty submerged in water with only the hand holding a torch and top of the crown visible.

The US government ordered that art made by inmates at the detention centre would have to be destroyed when they are released after an exhibition of works in New York in 2017 sparked controversy.

"Any artist who can't show their work because someone prevents them from doing so is an artist who is censored, and therefore will always have a place in this museum," Benet said.

'Amazed'

Benet was speaking a few metres from a self-portrait of late US artist Chuck Close, known for his massive photorealistic portraits.

The National Gallery of Art in Washington gave up dedicating an exhibition to Close's works after several women accused him of sexually harassing them several years earlier when they came to his studio to pose.

Benet said having so many controversial works together caused visitors' "levels of tolerance to widen and the level of scandal of the work to be lowered".

Corinna Dechateaubourg, a 56-year-old German who was visiting from Hamburg on the exhibition's opening day, said she kept looking up more information on the works on her mobile phone.

"I'm amazed, it's extraordinary, it's really interesting," she told AFP.

Montserrat Izquierdo, a 67-year-old Spaniard, said "it is good to be able to see what is forbidden, what you are not allowed to see normally".