An Australian judge ruled on Friday that best-selling author Colleen McCullough's widower was the sole beneficiary of her estate following a bitter court wrangle.

The author of the novel "The Thorn Birds," which sold 33 million copies worldwide, died on Norfolk Island in 2015 aged 77.

Her husband of 32 years, Ric Robinson, had been battling the executor of the author's estate and close friend, Selwa Anthony, in the New South Wales state Supreme Court over who was entitled to her 2.1 million Australian dollar ($1.5 million) estate.

McCullough wrote a will in 2014 leaving everything to The University of Oklahoma Foundation, of which she was a founding board member. Anthony alleged Robinson took advantage of his wife's ill health to change her will in October 2014, leaving him everything, before her death four months later.

Anthony maintained the foundation was the rightful beneficiary according to the earlier will signed in Sydney, around the time McCullough said she had "kicked Ric out for good" because he had a mistress.

Justice Nigel Rein on Friday found McCullough had intended to bequeath her entire estate to Robinson.

He found the foundation will was later revoked following the couple's reconciliation, when McCullough signed or initialed documents leaving everything to her husband.