The cousin of Monaco’s reigning prince was last seen staggering out of a nightclub, and hours later he was found dead behind the national museum.
The body of Antoine de Massy, 29, was found on Sunday, Oct. 25, 2026, in a small park tucked behind Villa Sauber, home of the New National Museum of Monaco, along the Boulevard du Larvotto. He was a first cousin once removed of Prince Albert II. Autopsy findings point to a fall of roughly 40 feet from a nearby building, and prosecutors have now charged a 42-year-old Ukrainian man with involuntary manslaughter and with failing to help someone in danger.
Prosecutors say it is still unclear what part, if any, the man played in the death. “All hypotheses are on the table, including that of a simple accident,” the office said in a statement.
The Prince’s Palace said Monday, Oct. 26, that Albert II and his wife, Princess Charlène, were saddened by the death of de Massy, the grandson of Princess Antoinette, the elder sister of Albert’s father, Prince Rainier III.
Missing From the Family Lunch
De Massy was reported missing after he failed to appear for a family lunch. He had last been seen staggering out of a nightclub in the early hours of that Sunday morning. His body was discovered in the park shortly afterward.
Authorities in Monaco said late Monday, Oct. 26, that they had detained a man and opened an investigation into the death of a member of the princely family. They were still working to determine the cause of death.
CCTV Put Him Near the Body
Police arrested the Ukrainian national that same Monday after CCTV footage showed him near the spot where de Massy’s body was found. The man, 42, has lived in Monaco for three decades. Investigators established that he had been in contact with de Massy.
He appeared before a judge on Wednesday, Oct. 28, and denied the charges, declining to respond to any questions. Stéphane Thibault, Monaco’s prosecutor general, said the alleged offenses may not all date from the same moment.
A prosecutor said the legal framework of the case had to be altered so the man could be placed in police custody and the circumstances of the death clarified. Separately, rumors have circulated about a possible link between de Massy and a cryptocurrency scandal. Those reports are unverified.
From Bollettieri’s Academy to a Startup
Long before the tech world, de Massy chased a future on the tennis tour. He said in a 2012 interview that his father first put a racket in his hands when he was three years old, and that his dream was the world’s top ranking. His family relocated to Florida while he was still young so he could train at the Nick Bollettieri Tennis Academy.
He later turned to business, founding the technology firm Instant Tech in 2021, a platform built to connect local businesses with customers through instant reservations and payments.
The 42-year-old is being held in pretrial detention while investigators work to establish the sequence of events that ended in de Massy’s fall. Princess Antoinette, his grandmother, died in 2011 at age 90.
In its statement, the palace remembered him as an avid player from a family long tied to tennis in Monaco.