Bryce Courtenay: Advertising executive who went on to become a blockbuster author

He was known to exaggerate. 'I take a fact, put a top hat on it, a silk shirt and a bow tie,' he said

Bryce Courtenay was well into his fifties when he published his first novel, The Power of One. Intended to be a "practice book", it sold more than six million copies worldwide. Over the next two decades he pumped out a blockbuster each year, earning sneers from some in Australia's literary scene but single-handedly boosting the fortunes of local publishers and booksellers.

South African-born Courtenay saw his role as "essentially that of an entertainer, no different to that of a musician, no different to that of an actor. I just happen to be an author." His gift was storytelling, and he unashamedly embellished his own life story, too.

A consummate professional, he wrote for 12 hours a day, six days a week, delivering a doorstop-sized novel to his publishers each November, in time for Christmas. On 12 November this year, his 21st book, Jack of Diamonds, was published. Ten days later, Courtenay died of stomach cancer after recording a farewell video message to his fans.

Tributes to the author, who regularly topped Australian bestseller lists and enjoyed sales of more than 20 million worldwide, came from all quarters, including the Prime Minister, Julia Gillard. The Booker Prize-winning author Thomas Keneally said writers such as Courtenay and JK Rowling enabled "thousands of flowers to bloom", with their works financing "the publication of books that might sell more humbly".

Courtenay's boyhood could make a racy novel, although elements of it are disputed. The illegitimate child of a dressmaker mother, he was born in Barberton, a small town in the mountains of north-eastern South Africa, in 1933. He spent part of his early life in an orphanage – years, he says; according to his sister, Rosemary, it was weeks or months.

He later attended the prestigious King Edward VII School in Johannesburg. (He said he won a scholarship; Rosemary says their father, a married clothing salesman named Arthur Ryder, paid the fees.) He then worked in the copper mines of what was then Rhodesia, where, he claimed, he never showered without a knife or pistol, to avoid being raped.

With the money he saved he travelled to England, where he studied at the London School of Journalism. He also met an Australian, Benito Solomon, whom he married in 1959 after the couple moved to her native Sydney.

In Australia, Courtenay embarked on a 30-year career in advertising which saw him become one of the industry's most successful creative directors. He also worked ferociously long hours and by his mid-fifties was "drinking several bottles of wine a day and smoking 100 cigarettes".

Health concerns prompted him to sell his agency and begin running marathons. He also embarked on The Power of One, about a boy's journey to adulthood in apartheid-era South Africa. Published in 1989, it was made into a film starring Morgan Freeman. It earned Courtenay a million-dollar advance, and although none of his subsequent novels was quite as successful, they each added more than A$10m to the Australian book trade's turnover, according to his long-time publisher at Penguin, Bob Sessions.

One of Courtenay's only two non-fiction works was based on personal tragedy: the death in 1991, aged 24, of his youngest son, Damon, a haemophiliac who contracted Aids from a contaminated blood transfusion. April Fool's Day, a memoir, was published two years later, and is credited with helping to transform public attitudes towards the disease.

While Australians loved his books – reportedly one in three households owns at least one – it rankled with Courtenay that he never enjoyed critical acclaim. He branded Peter Carey a "literary snob" after the award-winning author rebuked Australians for "forgetting how to read". And, Courtenay claimed, it was much harder "to make it into the top 100 fiction writers in the world than it is to write a book which the local literati feel is splendid and sells 2,000 copies."

The former adman was always closely involved in promoting his own work, devising stunts such as sky-writing and branded beer. Always gracious to his fans, he would request the address of anyone who stopped him in the street and send them a signed book. He was generous with advice to younger authors, and supported numerous charities.

Of his propensity to exaggerate the facts of his own life, Courtenay once declared: "I take a fact, put a top hat on it, a silk shirt and bow tie and striped trousers and a tailcoat and a pair of tap shoes and I do a Fred Astaire with a fact. But I don't ruin the fact ... I'm just giving it life."

Although he divorced Benito in 2000, the couple remained close, and he was at her bedside when she died of leukaemia in 2007. He married Christine Gee, the twin sister of one of Australia's best-known literary agents, Margaret Gee, last year. (Courtenay had also had a relationship with Margaret.) He was made a member of the Order of Australia in 1995, received two honorary degrees and was one of six authors celebrated on a collection of "Literary Legend" Australian stamps issued in 2010. Carey was among the others.

Bryce Courtenay, advertising executive and author: born Barberton, South Africa 14 August, 1933; married Benita Solomon (divorced 2000; two sons, and one son deceased); Order of Australia 1995; married 2011 Christine Gee; died Canberra 22 November 2012.