Australia's Gina Rinehart is 'world's richest woman'

Australian mining magnate Gina Rinehart has become the world's richest woman, according to the country's respected business magazine BRW.

It says Ms Rinehart, 58, is now worth A$29bn ($28bn; £18bn), having increased her wealth by nearly A$20bn in a year.

It is now possible that she could become the world's first $100bn person, the magazine says.

It says the heiress to an iron-ore prospecting empire earns A$52m a day, A$1m every half hour or A$600 a second.

"The increase in her wealth is unparalleled. It is a product of foreign investment in new projects, increased production and a recovery in the iron-ore price over the past six months," BRW wrote.

Ms Rinehart's rise in wealth means she now surpasses the $25bn of Christy Walton, the widow of the founder of America's Wal-Mart retail chain.

However, Ms Rinehart has caused controversy by campaigning against government attempts to tax mining companies, the BBC's Duncan Kennedy in Sydney reports.

She has also been involved in a nasty fight with three of her four children over control of the family trust, our correspondent adds.