Joern Utzon was pushed off the original opera house project before the building was finished. The opera house involved years of delays, cost overruns and bitter disputes with the government of New South Wales state, of which Sydney is the capital. Utzon's design, selected in 1957 from more than 230 entrants in an international competition, was supposed to be built in four years after construction started in 1959. Fourteen years later, Queen Elizabeth II finally declared it open.

While the exterior of Utzon's design — which at the time tested construction technology as well as visual concepts of a building — was retained, Australian architects who took over in 1966 changed the interior and other features under instructions to cut costs and get the building finished quickly.

Years later, public outrage at the cost overruns waned, the building became a national point of pride and the failure to achieve Utzon's original vision for it is largely viewed as tragic.

The building became Utzon's greatest triumph, though the success was tinged with bitterness. He was awarded the Pritzker Prize for architecture in 2003, when judge Frank Gehry — a Pritzker-winning architect himself — wrote that Utzon had "persevered through extraordinary malicious publicity and negative criticism to build a building that changed the image of an entire country."

But Utzon never returned to Sydney and never saw the completed opera house.

In 1999, after the public mood had changed, Utzon was invited to draw up design plans that would guide any future work. A series of improvements was announced in 2002, with Utzon and son Jan appointed as part of a team overseeing the $36 million project.

A new colonnade and loggia have been completed, and refurbishment of some foyers is due to start later this year. Plans are also being considered to redo the concert hall and opera theater so they will be more in line with Utzon's original design.

Drew told the AP that the work done so far is "out of harmony" with the building. He said that the Sydney Opera House Trust was being too secretive about the project and was putting Utzon's name ahead of the integrity of the building — claims the trust has denied.

The Opera House Trust said in a statement that it was publicly known that Utzon's eyesight "is not what it has been." But having Utzon on the project was an "extraordinary privilege" that "afforded us the rare opportunity of once again benefiting from Joern Utzon's unique insight, ideas and genius."

Utzon has no plans to visit Sydney, his son said.