A cousin of Monaco’s reigning prince walked out of a nightclub leaning on someone in the early hours, and hours later he was found dead in a park behind the principality’s national museum.
Monaco prosecutors have charged a 42-year-old Ukrainian man with involuntary manslaughter and failing to help someone in danger in the death of Antoine de Massy, 29, a first cousin once removed of Prince Albert II, whose body was found Sunday, Oct. 25, 2026, in a small park behind Villa Sauber, home of the New National Museum of Monaco, along the Boulevard du Larvotto.
Autopsy findings point to a fall of about 13 meters, or roughly 43 feet, from a building near the Boulevard du Larvotto. Prosecutors say it is still unclear what part, if any, the charged man played in the death.
“All hypotheses are on the table, including that of a simple accident,” the office said in a statement.
De Massy was reported missing after he failed to show up for a family lunch. He had been seen stumbling out of a nightclub, leaning on someone, in the early hours of that Sunday morning. His body turned up in the park that evening.
The Man on the CCTV Footage
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.
Police arrested the Ukrainian national that same Monday after CCTV footage showed him near the spot where the body was found. The man, 42, has lived in Monaco for three decades, and investigators established that he had been in contact with de Massy.
He appeared before a judge Wednesday, Oct. 28, and declined to answer questions. During police questioning, he had disputed the allegations. He was placed in pretrial detention.
Stéphane Thibault, Monaco’s prosecutor general, said the alleged offenses may not all date from the same moment.
His Father Rules Out an Accident
Christian de Massy, Antoine’s father, rejected the accident theory. He told Italian media that he rules out both an accident and suicide, and he said his son did not know the 42-year-old man.
Rumors have circulated of a possible link between de Massy and a cryptocurrency scandal, though those reports are unverified.
A Crocheted Dog in the Coffin
The Prince’s Palace said Monday, Oct. 26, that Albert II and his wife, Princess Charlène, were saddened by the death. Both attended the funeral at Monaco Cathedral on Wednesday, Nov. 4.
At the service, Christian de Massy placed a small crocheted replica of his son’s dog, Tounin, in the coffin. Burial was planned at the Monaco cemetery.
De Massy was a grandson of Princess Antoinette, the elder sister of Albert’s father, Prince Rainier III. Princess Antoinette died in 2011 at age 90.
Long before the tech world, he aimed at the tennis tour. In a 2012 interview, he said his father first put a racket in his hands when he was three, and that his dream was the world’s top ranking. The family relocated to Florida while he was young so he could train at the Nick Bollettieri Tennis Academy.
He later co-founded the technology firm Instant Tech, a platform built to connect local businesses with customers through instant reservations and payments. The palace statement remembered him as an avid player from a family long tied to tennis in Monaco.