It is America’s wealthiest postcode – 216 acres of tropical gorgeousness and palatial living reachable only by private ferry, yacht or helicopter.

Surrounded by sand imported from the Bahamas, planted with orchids and palms brought from the Indian Ocean and South Pacific, and a-twitter with the sound of caged toucans and macaws that enjoy daily outings with a bird walker, Fisher Island is known as Fantasy Island. So monied are residents of the enclave, three miles off Miami, it is said that if you waved at everyone you saw in a ten-minute drive there, you would have waved at more than $1 billion (£500 million).

But those who tend its manicured lawns and golf course, guard its residents’ riches, shine their Bentleys and Lamborghinis and wash their champagne glasses for as little as £40 a day, have had enough.

In a case highlighting the upstairs, downstairs hierarchy, its mainly black and Hispanic workers accuse management and some home owners of racial discrimination, abusive treatment and unfair wages.

“When you have the super-rich who can have a little isolated fantasy island of their own, they unfortunately develop a plantation mentality, and that’s what the workers are dealing with; people who see them as workers, not as human beings,” said Magdaleno Rose-Avila, executive director of Interfaith Workers Justice, an advocacy group.

Fisher Island is the epitome of the growing divide between rich and poor, says the Service Employees International Union (SEIU), and it has become the battleground for a workers rights campaign.

Claiming that their dignity and human rights have been violated, the SEIU and 19 employees have filed a class-action complaint with the Miami-Dade County Equal Opportunity Board alleging, in particular, that Fisher Island’s private ferry service, which makes the 15-minute trip to and from the mainland, exercises segregationist policies. “There is terrible discrimination on that ferry. When you get on, it’s whites on one side, blacks on the other,” Mariette Casseus, a housekeeper, said.

While residents relax in an air-conditioned lounge, employees must spend the trip in a separate room whose cooling system is often broken, they say. If they do not board the ferry before residents have driven their cars on, they are not allowed to squeeze past the vehicles to reach their room because they might sully the bodywork with smudges or fingerprints.

“Rather, the employee passengers are forced to stand under an outside awning that fails to protect them from heavy rain, debilitating heat, severe wind and ship fumes,” the complaint alleges. Seshma Sheth, of the Miami Workers Centre, said: “We are seeing two Americas, we are seeing two different worlds and Fisher Island typifies that. To get on that ferry, it’s basically taking a trip back in time. You are going back to a racist and backward time . . . We market Miami as a city of the future and then we have this island that’s just a throwback to our past.”

The first owner of Fisher Island - created by dredging the sea off Miami Beach in 1905 – was Dana Dorsey, south Florida’s first black millionaire.

In 1925, it was bought by William Kissam Vanderbilt, a member of one of America’s wealthiest families, who built a winter estate that is now a luxury hotel.

The public are not allowed on to the island unless invited and the privacy of its mainly white residents – largely financiers, corporate executives and property barons with little public name recognition who live there part-time – is fiercely guarded. Aides to the President of Venezuela, who visited in the 1980s, commented that it was easier to gain access to the White House than to Fisher Island.

Oprah Winfrey, Julia Roberts, Boris Becker, Robert De Niro, Sylvester Stallone, the founder of the Samsonite luggage empire and the heir to the Bacardi rum fortune have all, at some time, had homes there.

The latest census, in 2000, gave the population as 467 and the island operates as a private club where cash is not required, just a membership card. It has eighteen tennis courts, two marinas and a heliport. Some residents are even rumoured to have paid for separate apartments for pampered pets.

The island’s management says that it works hard to address workers’ issues. But in a protest staged at the weekend, 100 SEIU activists “invaded” Fisher Island’s exclusive beaches to protest against the community’s perceived social failings. “Because they are so isolated, Fisher Island residents think they can wall themselves off from the poverty they create,” Hiram Ruiz, an SEIU representative, said. “We set out to make a point: there should be only one Miami, not one Miami for the wealthy and another for the rest of us.”

Island strife

$17.5m cost of a 8,300 sq ft seaside property

$236,000 average income per capita

467 number of residents

51 average age of residents

0.3 size in square miles of Fisher Island

Source: Times database, fisherisland.com

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