Mining magnate Andrew “Twiggy” Forrest and his wife Nicola will donate $400 million to be used for a number of causes, including cancer research and the eradication of slavery.

The donation was described by Prime Minister Malcolm Turnbull as the “the biggest single philanthropic gift” in Australian history, and the largest donation by living Australian.

Mr Forrest, the founder of mining company Fortescue Metals, is estimated by Forbes to have a net worth of more than $5.5 billion.

Mr and Ms Forrest have a long history of donating to philanthropic causes.

“I have been very fortunate, with my wife, Nicola, to be able to accumulate capital, and then as soon as we can to commence giving it away,” Mr Forrest said.

“We had a slightly unsustainable business model previously, where we would actually borrow money to give it away.

“Fortunately, we don’t have to do that now, thanks to the strength of the iron ore sector.”

Mr Turnbull said the money would be put to a range of initiatives, including fighting cancer, investing in higher education, and ending slavery.

“It is a game-changer in the Australian philanthropic community. And it will change the lives of thousands of people here in and around the world,” Mr Turnbull said.

“But all of us should seek to do as much as we can with what we have. So, this is real leadership and leading by example.”

Mr Forrest was the Western Australian nominee for the 2017 Australian of the Year for his work in highlighting Indigenous disparity and advocating for the end of modern day slavery.

While today’s donation is the largest made by living people, in 2014 healthcare and media entrepreneur Paul Ramsay left about $3 billion to his personal foundation when he died.