In a statement on Sunday, NSW Premier Gladys Berejiklian described the designer as 'talented, generous and inspiring. A true trailblazer in every respect'.

"On behalf of the people of NSW, I extend my deepest condolences to the family, friends and colleagues of Carla." the statement said.

Details of the State Funeral will be provided in the coming days.

Tributes continue for Zampatti, 78, who died at Sydney's St Vincent's Hospital on Saturday morning.

The mother-of-three and grandmother to nine had spent a week in hospital after falling as she attended an outdoor opening performance of Opera Australia's La Traviata in Sydney.

Opera Australia has acknowledged the tragic death but has not responded to a report of 'dangerous' stairs at the performance.

"Opera Australia is deeply saddened by the news of Carla Zampatti's passing," a statement read.

"Ms Zampatti was an Australian fashion icon and a passionate supporter of the arts who will be greatly missed.

"Our thoughts and heartfelt sympathies are with her family at this time."

Opera Australia was asked to respond to comments from Zampatti's contemporary and ABC Chair Ita Buttrose that the stairs were dangerous and needed improvement.

"The stairs are very dangerous at the opera," Buttrose told ABC TV.

"Install some rails because otherwise other people might fall as well."

Born in Italy in 1942, Zampatti migrated to Australia in 1950 at age nine, setting up her fashion famous label at 24.

Her designs have been worn by some of Australia's most influential women, including Princess Mary of Denmark, Australia's first female prime minister Julia Gillard, Oscar-winning actress Nicole Kidman and Ms. Berejiklian.

"Carla has long been celebrated for making Australian women feel confident and elegant through her exceptional design, tailoring and understanding of the modern woman," her family said in a statement.

Zampatti was named Australian Designer of the Year in 1994, awarded the Australian Fashion Laureate in 2008 and a year later was appointed a Companion of the Order of Australia, Australia's highest civilian honour.

Daughter Bianca, who followed in her mother's footsteps as a designer, posted an emotional tribute to her "inspiration" on Instagram.

"Today I lost my mother, my inspiration, my mentor and my friend. I am lost for words and totally heartbroken," she wrote.

"She leaves an undeniable legacy behind, and will remain a constant in the hearts of her loving family, friends and women all over Australia."

Prime Minister Scott Morrison also paid tribute, saying it had been a great honour to have known her.

"Carla was an icon to the fashion industry, a pioneer as an entrepreneur and a champion of multicultural Australia," he said.

"Her contribution to our nation will be timeless, just like her designs."

Australian Associated Press