Janie Osborne/AP Photo

Gary and Angelica Di Silvestri may have seemed like the unlikeliest of Olympians when they appeared during the opening ceremony in Sochi, Russia, to represent the tiny Caribbean island of Dominica in the Winter Olympics.

Gary Di Silvestri, 47, a Staten Island native and former hedge fund manager, and his 48-year-old, Italian-born wife live in a $20 million mansion in Montana, but the cross-country skiing pair made headlines as Sochi's oldest Olympians and the first husband-and-wife competing in the same event.

U.S. Citizens on Way to Olympics, But Not Repping the USA

"To have him here with me, it's special," Angelica Di Silvestri told NBC News in Sochi. "I wouldn't be here without him."

"Nor would I without her," said her husband.

But with no residence and no family in Dominica, some critics say the couple had no right to be Olympians.

The Di Silvestris certainly aren't the only Olympians to have competed for a country other than their birth nation. American citizens have competed as boxers for Mexico, bobsledders for Armenia and Greece, and lugers for Venezuela.

Athletes can compete for another nation if they have a parent or grandparent from there. Some countries also allow for athletes married to a citizen of that country or with a birth certificate from that country to compete.

A Pew research study found that at least 120 Sochi athletes competed for countries other than their birth nations - but most had some ties to the other nation.

To qualify for the Olympics, which ended on Sunday, the Di Silvestris had to meet minimum performance standards and be full citizens of the nation they were representing, and Dominica had to have a governing body for the sport.

While they often skied near the back of the pack in pre-Olympics races, they still managed to qualify. The head of Dominica's national governing body for skiing is Gary Di Silvestri.

Dominica, a former British colony with around 70,000 inhabitants and a tropical climate, provides citizenship to married couples who give at least $175,000 to the country.

In an interview with the New York Times before the couple left for Sochi, Gary Di Silvestri said he wanted to help the country.

"They needed assistance, so did we. We acted the best we could at the time, made a financial contribution to the country that went to different projects, and in return they granted us citizenship," he said.

Felix Wilson, the president of the nation's Olympic Committee, stood by the Di Silvestris, telling the San Diego Tribune in an email: "The Di Silvestri family did NOT 'buy' their way to the Winter Olympic Games. Nothing was pre-arranged or pre-planned but done on merit after much sacrifice. There has been no violation of Olympic rules and principles."

The pair didn't do well in their sport. Angelica Di Silvestri reportedly skied off course during training and broke her nose, missing her race completely. Her husband reportedly came down with a stomach illness and collapsed 300 meters into his 15 kilometer event.