At the back of a police station in the Italian capital of Rome is a warehouse that holds one of the most valuable art collections in Europe.
Behind the armoured door is a vault that looks like it belongs to a compulsive hoarder.
But instead of being filled with trash, it is an Aladdin's cave of treasure.
Works from Picasso, Banksy, Warhol, Modigliani and a $300 million Van Gough are found alongside carefully labelled bronze statues and marble busts.
But there is a reason this coveted haul isn't on public display — everything is either stolen or fake.
The artefacts have been recovered by the Italian Carabinieri Art Squad.
They're an elite branch of the police force, with 300 investigators devoted to protecting Italy's cultural heritage from tomb raiders, art thieves and painting forgers.
The items are stored at the force's headquarters until they are returned to their rightful owners or used as evidence in criminal trials.
Lieutenant Colonel Diego Polio has been with the squad for over a decade.
He told the ABC an increased demand for contemporary art has fuelled a boom in forged works.
Organised crime running forgery labs
Last month, his officers raided an art forgery workshop in Rome and seized 71 fake paintings copied from some of the world's most famous artists, including Picasso and Rembrandt.
"Scanning the web, we found an e-commerce site of a restorer selling many paintings of contemporary art in a way that was suspicious," he said.
"We found he had a forgery laboratory here in Rome, he painted many contemporary art paintings, faked authentication and sold them online for hundreds of thousands of dollars."
Earlier this year, the squad arrested 38 people across four European countries.
They're suspected of being part of an organised crime syndicate that has produced more than 2,000 replicas of paintings by Banksy, Warhol, Monet and Dali, which had a total value of $340 million.
The squad has tracked down millions of stolen authentic artworks, including a 500-year-old copy of Leonardo da Vinci's Salvator Mundi — the world's most expensive painting.
The $450 million piece was believed to be painted by one of da Vinci's students and looted from a museum in Naples.
The illegal art trafficking trade is one of the world's biggest, and generates billions of dollars on the black market each year.
Millions of stolen items recovered
Italy was the first country to set up a dedicated art police unit in 1969.
Since then, it has recovered more than 3 million artworks and artefacts.
Lieutenant Colonel Polio said his investigators start as police officers, before they get specialised training in art history, restoration and recognising counterfeit works.
"All of our police officers come from other units, they must be experienced and they have to pass an exam and undertake a course about art and archaeology," he said.
"We use traditional investigation techniques like phone taps, undercover officers, surveillance and fake websites to attract people who want to trade illegally cultural goods."
There is also a special branch of the force that target thieves who raid tombs, using helicopters, drones and divers as surveillance.
Italy has the most cultural heritage sites in the UNESCO World Heritage List, making it a prime target for thieves known as the "tombaroli" or tomb robbers.
They smash their way into ancient burial chambers, mainly in the centre and south of Italy, to recover vases, ornaments, jewellery and medieval pottery from ancient Roman times.
Lieutenant Colonel Polio said many of these sites are under the ocean and require sea patrols and submariners.
"We use drones and helicopters to try to find illegal excavations before they can steal from the areas and sell them abroad," he said.
"Illegal excavations in Italy are a big problem because we have more than 600 archaeological sites, that we know of."
AI helps find stolen treasures
Other countries have followed Italy's lead and created their own art squads, but none have replicated the Carabinieri's success.
The FBI's Art Crime Team in the United States was founded in 2004 and has 30 agents, one tenth the size of the Carabinieri team.
The Carabinieri doesn't just focus on Italian art, it works with other countries to recover stolen items from across the world.
In 2023, investigators found a stolen 2,500-year-old Mediterranean amphora at Australia's National University (ANU), which was likely smuggled out in piles of pasta.
The ANU bought the vase, which depicted Greek champion Heracles fighting a mythical lion, in good faith from Sotheby auction house in London in 1984.
"When we find an item abroad in another country, but there is no criminal activity, we can use cultural diplomacy to try to recover it and to take it back to our nation," Colonel Polio said.
Lieutenant Colonel Polio said the force's secret weapon is AI.
It's called SWAD — The Stolen Works of Art Detection database.
With 8 million registered items, it is the largest of its kind in the world.
"It's an artificial intelligence system that scans the web and when it finds something we know is stolen, for example on an e-commerce site, it sounds an alert and we start an investigation," he said.
If you try to buy a Picasso or Banksy online, Lieutenant Colonel Polio said there is a good chance you will have an Italian detective looking over your shoulder.
"I have always thought that the best skill that an investigator must have is to be creative, you need to think outside the box and have smart ideas," he said.
"My favourite part of the job is handing back stolen items.
"You find the people are very happy, sometimes they cry, especially when they are objects of religious origin and for us it's very positive to return these items to the communities."
