The last book has been published, the last film released, but the Harry Potter phenomenon continues to grow, with a new theme park set to open in Hollywood.

Hogwarts Castle is expected to be conjured up at Universal Studios Hollywood theme park as part of a Harry Potter attraction there.

Comcast, the cable TV giant which owns the majority stake of NBCUniversal, is said to be in the final stages of the deal. It will be the second such attraction; the first opened in Orlando, Florida, last June with a grand ceremony attended by JK Rowling, Daniel Radcliffe, who played Harry Potter in the films, Rupert Grint, Michael Gambon and a host of other cast members.

Another theme park would likely add to JK Rowling's fortune, estimated at more than £560 million. Worldwide sales of the seventh and final book alone, Harry Potter and the Deathly Hallows, are well in excess of £400m and the final instalment of the Harry Potter film series took £706m worldwide.

Ms Rowling said of the Orlando attraction when it opened: "I'm used to walking on to film sets where at a certain point everything dissolves into scaffolding and lighting, so I suppose the completeness of the vision is what's really breathtaking here."

NBCUniversal has not commented on the report of a new Hollywood Potter attraction, published in the Wall Street Journal. The paper also suggested similar Potter-themed sections could open in other Universal theme parks around the world, such as Japan and Singapore, if the Hollywood one is a success.

As for the UK, there has been no word on whether Harry's Potter's home country could get its own version of the Wizarding World, though a Harry Potter-themed studio tour is due to open at Warner Bros' Leavesden Studios, the production home of the seven films, in spring 2012.

The Making of Harry Potter tour will allow visitors to step inside the Great Hall as seen in the films, explore Dumbledore's office and see famous props like the Sorting Hat, Harry's Nimbus 2000 and Hagrid's motorcycle.

The new Los Angeles attraction is expected to be much like the Orlando one, with Potter-themed rides and replica shops, perhaps including Mr Ollivander's, where young witches and wizards can buy their first wands, and Honeydukes, the sweet shop where the big sellers include Bertie Bott's Every Flavour Beans.

The Orlando park, described by its creators as "truly the most spectacular themed entertainment area ever created in history", contains three rides, Flights of the Hippogriffs, Dragon Challenge rollercoaster and Harry Potter and the Forbidden Journey, taking visitors through Hogwarts scenes, as well as a Hogwarts Castle and a replica of Hogsmeade village, permanently covered with "snow" in spite of the Florida sunshine.

Rowling was consulted by NBCUniversal on many points of detail. Mark Woodbury, head of Universal Creative, revealed the author was asked to try a succession of recipes in an attempt to get the right texture and taste for butterbeer. He said: "We had to package up all the ingredients and rent a hotel kitchen in Scotland so that we could put it all together."

Since the Potter park in Orlando opened, attendance at Universal Orlando has jumped by 40%-50%.