The Prestons-based company JVPlay said the development would be ‘‘unlike anything seen in Australia and will cater for the NSW population who are greatly lacking a major themed or leisure environment’’.

The company act as agents for international companies that specialise in play concepts, leisure amusements, theming, water play and developments.

Directors Julianne and Vincent Cusumano said they were looking at sites in the Leppington or Bringelly areas, with the concept needing about 60 acres. The group does not yet have land or a site in mind.

Stage one of the concept – the Great Reef Resort – would include indoor and outdoor water parks, a 200-room hotel and conference facilities for trade shows and weddings. Stage two includes a theme park with rides which have never before been seen in Australia, and extensive parklands.

‘‘This is bringing the families back together without those exuberant prices of going up to Queensland,’’ Ms Cusumano said.

‘‘It will generate a minimum of 450,000 visitors to this area, where they will spend additional dollars on restaurants, transportation, retail and merchandise.’’

International companies have travelled to Sydney to talk about the proposal, with JVPlay representatives also touring the US to look at indoor and outdoor water park ideas.

Ms Cusumano, from Liverpool, and national sales manager Andrew Green, from Bradbury, say that as locals they know what local people need and want to be entertained.

Mr Green and Ms Cusumano met NSW Government representatives Western Sydney Minister David Borger and State Development Minister Ian Macdonald to show them the plan, and also Opposition Leader and western Sydney spokesman Barry O’Farrell.

A spokeswoman for Mr Borger said he was interested in hearing about the ideas for a theme park.