CATHERINE ZETA-JONES and Michael Douglas are about to splash out on their seventh home, according to latest reports from the US.

The film star couple are believed to have bought a five-bedroom residence on a private island in the Turks & Caicos islands, in the idyllic British West Indies.

The £3.5m ($7m) yet-to-be- built home will be located on Dellis Cay where houses and apartments and a top quality hotel are being developed on a 35-acre site.

Like Zeta-Jones's home in her native Swansea, her new property will be on a prime beachfront site.

There the similarities end, though, with the development taking place on an island that boasts protected mangrove reserves and sheltered coral reefs amidst deep turquoise seas.

One expert said the latest addition to the couple's burgeoning property portfolio would benefit the developers as well as the stars themselves.

Charlie Ellingworth of Property Vision, which finds homes for wealthy buyers, says the presence of celebrities gives housing developments a big boost in terms of sales.

He said, "If the agent tells you Elton John lives down the street, you become rich or famous by association."

He added, "Some homes have celebrity longevity. Ava Gardner used to live on Ennismore Gardens (in London) and 15 years after her death it is still known as the Ava Gardner home. The same for Noel Gallagher's home in Primrose Hill. Although it has changed hands over the years, it is still known as Supernova Heights."

It will be equipped with tennis courts, sun decks and infinity pools, while a spa that will be suspended above a tranquil lake is being constructed by Japanese designer Kengo Kuma.

Privacy will be assured as the cay, or low-lying island, can only be reached by well-equipped boats or chartered helicopters.

The island is being designed by Italian architect Piero Lissoni to have a chic, contemporary style with Asian influences reflecting the oriental roots of developers the Oriental Mandarin Hotel Group.

The star couple's purchase was reported in respected US journals The New York Post and The Denver Post .

The hotels and apartments on what will be known as the Mandarin Oriental Dellis Cay are not scheduled to open until 2009, but its marketing efforts have already started in earnest and construction work is due to start next month.

The private island is named after Greek shipping magnate John Dellis who developed a thriving sponge trading centre at this particular cay towards the end of the 19th century.

There will be 25 suites in the hotel to add to the private residences plus a smattering of villas and condominium style apartments.

The residences will feature large terraces and balconies and there will be four restaurants plus a beach club and shops.

Catherine Zeta-Jones and Michael Douglas already have a multi-million-pound home nestling in the swish Colorado ski resort of Aspen, where they got engaged at the turn of the millennium.

And they maintain a luxury apartment in Manhattan, close to the Plaza Hotel where they tied the knot in November 2000.

The main Douglas residence now is in Bermuda where their children Carys and Dylan are receiving their education, and where Michael Douglas's mother Diana Dill grew up. Michael Douglas is said to have long-hankered after a property farther south "when the wind gets gusty".

The Hollywood couple also have a house in sunny Majorca, formerly the residence of Archduke Lodwig of Austria, another residence in Los Angeles and, of course, the house overlooking Bracelet Bay in Mumbles.

Page 2 - The Turks & Caicos islands v Catherine Zeta Jones's native Swansea

The Turks & Caicos islands v Catherine Zeta Jones's native Swansea

The Turks & Caicos Islands are named after the indigenous Turk's Head "fez" cactus, and the Lucayan (local native) term "caya hico," meaning string of islands and were discovered either by Christopher Columbus in the 1490s or fellow explorer Juan Ponce de Leon in 1512. Swansea, meanwhile, is named after the viking warlord Swayne who named it Swayne's Ey (territory).

The Turks & Caicos have a population of 22,000, compared with Swansea's 230,000

The climate in the Turks & Caicos is tropical, while Swansea locals joke, "If you can see Mumbles Head clearly, it is going to rain, if you can't, it is raining."

The Turks & Caicos' biggest claims to fame are that it was the base for Peter Benchley's hit novel The Island in which latter-day pirates prey on shipping and it is the only country to lie directly in the traditional boundaries of the Bermuda Triangle. Swansea has come up with Dylan Thomas, Harry Secombe and, of course, Catherine Zeta-Jones.

The governor of the Turks & Caicos is Richard Tauwhere, based in the islands' administrative centre on the island of Grand Turk. The leader of Swansea Council is Chris Holley based in the city's County Hall.

The best beaches in the Turks & Caicos are said to be on Parrot Cay, Salt Cay and Grand Turk. Swansea's are all based in the Gower peninsula, at Rhossili, Oxwich, Langland and Llangenith.

Both places have a history of piracy.