Antoine de Massy, a cousin of Prince Albert of Monaco, is believed to have fallen 40ft to his death after his body was found in a public garden on Sunday.
Questions have emerged over a possible connection to a cryptocurrency scandal, while a Ukrainian national has been arrested in connection with his death.
De Massy’s body was discovered behind the New National Museum, along Monaco’s Boulevard du Larvotto.
Reports say he was last seen staggering away from a nightclub in the early hours of Sunday morning.
The 29-year-old was reported missing after failing to attend a family lunch, according to local newspaper Monaco Matin. His body was found soon afterwards.
Police arrested a Ukrainian national on Monday after he was seen on CCTV near the location where De Massy’s body was found.
Investigators determined that the 42-year-old had been in contact with De Massy. However, he declined to answer questions when brought before a judge on Wednesday.
He remains in pre-trial detention and faces allegations of involuntary manslaughter and failing to assist a person in danger.
An autopsy has indicated that De Massy most likely died after falling 40ft from a building in the area.
Rumours have also begun circulating about a possible link between the 29-year-old and a cryptocurrency controversy.
Antoine de Massy’s body was found on Sunday in a public garden in Monaco
Prince Albert of Monaco and Princess Charlene said they were ‘saddened’ by Antoine de Massy’s death
Antoine de Massy (top right) pictured with members of Monaco’s royal family
An investigation by BILD reported that De Massy was active in Monaco’s blockchain community. Blockchain is a shared digital database that stores information across a network of computers.
He founded Instant Tech in 2021, a company connecting local businesses, merchants and customers for instant bookings and payments. He also co-founded the Association Cryptographique de Monte-Carlo.
A source cited by BILD claimed that De Massy may have had links to the controversial cryptocurrency exchange Zondacrypto.
Founded in Poland, the company is being investigated by authorities after collapsing in 2026, leaving thousands of customers unable to access their money.
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The losses are estimated at no less than 79.5 million euros, while Polish authorities are investigating suspected fraud and money laundering.
There is no proof of De Massy’s alleged connection to Zondacrypto. However, an insider close to the Grimaldi family told BILD that he was a prominent figure in Monaco’s technology sector.
‘It shows that Prince Albert II had placed his trust in the ambitious young entrepreneur. Without the prince’s approval, Antoine would not have been able to assume these positions in the tech scene,’ the source said.
Monaco has also faced heightened scrutiny from the Financial Action Task Force since 2024 and remains on the international grey list of jurisdictions considered high risk for money laundering.
The Financial Action Task Force has identified weaknesses in the principality’s efforts to combat money laundering.
The concerns include inadequate controls, shortcomings in investigations and weaknesses in tracking criminal assets.
His body was found in a park beside Monaco’s Boulevard du Larvotto
A BILD source claimed De Massy may have been linked to the controversial cryptocurrency exchange Zondacrypto
The prince’s palace announced De Massy’s death in a statement issued on Monday: ‘Their Serene Highnesses Prince Albert II and Princess Charlène were saddened to learn of the death of Antoine de Massy, the grandson of Princess Antoinette, the elder sister of Prince Rainier III.
‘A keen tennis player, he was part of a family history closely linked to the sport in the principality.
‘Their Highnesses share in the grief of his family and loved ones and offer them their sincere condolences at this painful time.’
De Massy played tennis professionally and moved to Florida with his family as a child to train at the prestigious Nick Bollettieri Tennis Academy, hoping to compete in the Olympics.
In a 2012 interview with Vogue Italia, he said his ambition was to ‘become number one in the world,’ adding that ‘even in the top 20 wouldn’t be bad!’
Despite his royal connections, BILD reported that he preferred to avoid the spotlight surrounding Monte Carlo’s social scene.
One of his final public appearances came at the traditional Te Deum Mass held for Monaco’s National Day in November 2025.
His father, Baron Christian de Massy, has often been described as the family’s black sheep. He was expelled from school and sent to Argentina after causing repeated trouble during his youth.
Local media have called him a playboy, and all four of his marriages ended in divorce. He is seldom seen attending social events alongside Monaco’s royal family.
