After thousands of rare Chilean cacti were found in the house of an Italian collector, a years-long trial slowly unravelled how they got there – and is setting a precedent for dealing with crimes of this kind.

At first sight, orange and off-white shards of rocks surrounded by dust and dirt are all you can see for thousands of desolate kilometres in the Atacama Desert of Chile. This is one of the driest places on Earth. Looking around, it feels impossible that any speck of life could survive.

But reaching out of nooks in the cracked crust along the desert's coast, there lie thousands of Copiapoa cacti. A cactus group made up of more than 30 species, Copiapoa are found only in Chile. They grow a mere centimetre each year in scorching, breathtaking desert conditions by absorbing the local evening fog, known as camanchaca.

These rare, aubergine-shaped succulents exemplify life's ability to adapt to extremes – one of the traits that has made them highly sought after by plant collectors.

They've also just been at the heart of a landmark trial over an international cactus heist that might revolutionise how biodiversity crimes are dealt with the world over.

Ranging from dark grey to blueish-green, and from the size of a coin to that of a small car, Copiapoa have thick dark spines along their geometrical ridges. Their fluffy friars head flowers white, yellow and sometimes orange once a year.

While they might look unassuming at first, their beauty, resilience and rarity have certainly not been lost on Andrea Piombetti.

A well-known personality in the Italian plant world, Piombetti has been cactus collector and trader for decades and is said to take great pride in his unique knowledge of the realm. His Facebook profile picture is a rugged backpack sitting on top of a cluster of cacti in the field. His WhatsApp status reads: "The King of the Cactus Pirates". He's been spotted clad in a jacket with "The King of Chile" printed on its back.

When called on his mobile number for this story, though, he refused to comment and hung up without saying a word. His lawyers were also contacted, but refused to comment.

In 2013, customs at Milano Malpensa Airport intercepted an unusual shipment of 143 cactus plants with visibly suspicious forged phytosanitary documents directed straight to his house in Senigallia, Ancona. Upon further inspection, police found even more boxes of cacti at his home and the home of a friend in a town nearby.

The team's botany expert was able to rapidly identify the cacti were Copiapoa, many of older than Piombetti himself. Soil forensics soon found they had been illicitly extirpated from their natural habitat in Chile and had no business in this man's home. Police issued an internal police warning across Europe about the discovery and the Italian government initiated prosecution. The case's statute of limitations, however, expired before the case verdict.

The case was dropped, and Lt Col Simone Cecchini, chief of the trade of endangered species unit of the local police force, believed any illicit trading had ceased. But when Cecchini returned to Piombetti's home again in February 2020, after receiving a complaint the collector had allegedly snuck out a rare sapling from a local nursery owned by botanist Andrea Cattabriga, Piombetti was resistant to letting the police into his home. He barricaded himself for about 10 minutes, says Cecchini.

Police did not find the rare sapling there, but once they gained entry what they found started a "much more interesting" case, says Cecchini. More than 1,000 Copiapoa cacti sat on Piombetti's veranda and in another locked room that he initially told police he'd lost the key for, together with other rare cacti. "It was by chance," says Cecchini of the discovery.

Piombetti also said he'd lost his passport, but police soon found it had been slid on top of his wardrobe. "He'd maybe thrown it there in a rush," says Cecchini. The document confirmed he'd visited Chile five times between 2016 and 2019.

Records found on his laptop and mobile helped police identify a close local accomplice, Mattia Crescentini, as well as a network of 10 other illegal plant traders and 10 regular buyers. The plants were usually sold online through specialised auction websites and bought by people with private ornamental collections all over the world. Crescentini posted his cactus on an Instagram account called Cactus_Italy. A Japanese buyer who works in the fashion industry, for instance, had been sending Piombetti sums of €2,500 (£2,100/$2,600) each month. Piombetti was also buying plants himself for hundreds of dollars.

The stolen plants discovered on that day were valued by the police at higher than €1m (£800,000/$1.1m).

Pictures of the crime scene were sent for plant identification – including to Cattabriga, who is local cactus expert. "These were incredible plants, they were ancient plants, hundreds of years old," says Cattabriga. Piombetti is known for having a keen, selective eye for high-quality specimens and precise collective methods, Cattabriga says. "They were perfect."

Forensic botanists from the botanical garden of Milan ran soil analyses to confirm that about 1,000 Copiapoa plants had been illicitly extracted straight from the Atacama Desert, and several hundred smaller, juvenile plants had been grown and propagated from seeds collected during those extirpation stints. While seed collecting in the wild is not illegal in Chile, removing and exporting plants without proper documentation is. In Italy, importing plants into the........

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