Aristotle Onassis' Granddaughter Splits from Husband, Rep Confirms

French-Greek heiress Athina Onassis de Miranda and her handsome husband Alvado "Doda" de Miranda Neto have separated, the Brazilian Olympian's spokeswoman confirms to PEOPLE.

"Anyone who has been through a separation knows how painful it is," the spokeswoman said, adding, "Doda Miranda and Athina Onassis were married for eleven years and on this journey they shared a life, a love for horses, for sports and for family."

A source close to the international equestrian tells PEOPLE that the split was caused by Miranda's alleged cheating.

"When Athina learned of Doda's cheating in March, she left Wellington, Florida, and has not returned," the source tells PEOPLE. "She initially fled to Belgium."



Miranda's spokeswoman slams reports of an affair, however, telling PEOPLE of the couple, "They maintain a cordial relationship and would like to be able to go through this painful moment with the maximum privacy and respect and not be the victims of any more defamation and dishonest news."

PEOPLE's attempts to reach Athina Onassis were unsuccessful.

Other sources in the equestrian community are still not sure, though, if the 11-year marriage will end in divorce.

"Doda has been dating the sister of another equestrian as well as engaging in a series of casual relationships," a source tells PEOPLE. "He has a reputation and their marital issues were the talk of the winter jumping season."

The heiress, 31, and Miranda, 43, spend winters show jumping in Wellington, the tight-knit equestrian community west of Palm Beach, Florida, where Jessica Springsteen, Georgina Bloomberg, Hillary Dobbs and Jennifer Gates also participate in the sport.

Although they live in Sao Paulo, Brazil, the couple spend portions of the summer jumping in different cities of Europe. They have also lived in Belgium with Miranda's two children from a previous relationship.

They bought a $2 million winter home in Wellington last year, and have a great deal in common, especially their passion for horses, riding and being around stables, barns and other horse-loving people.

Miranda is an Olympic gold medalist who may be part of the Brazilian team in this summer's Olympics in Rio de Janeiro.

"Athina and Doda are both accomplished and usually lead a low key existence in Wellington, their world centered around their horses and his children," another source tells PEOPLE.

"What happens now is anybody's guess."

• With reporting by DOM PHILLIPS