Because Ms Coates earns the majority of her wealth from her salary rather than dividends or other instruments, she is liable for a higher amount of tax than many other business chiefs. Ms Coates and her family are thought to have paid around £460m to HMRC last year.

She has also become a prominent figure in the arts industry, with a wing of the Courtauld Gallery in London named after her. 

The investigation into Bet365 comes as the Australian gambling industry faces pressure over gambling-related harms.

A 2022 study by the Australian Gambling Research Centre found that almost half of Australians aged 18 and over could be classed as being at-risk of or already experiencing gambling harm.  Australia is reportedly home to a fifth of the world’s slot machines.

Worries over rising harms have sparked a clampdown from the Australian government, with new laws such as a ban on online gambling companies accepting credit cards and digital currencies.

Brendan Thomas, the chief executive of Austrac, said: “Corporate bookmakers must have robust systems in place to ensure they can manage and mitigate risks associated with money laundering and terrorism financing.

“Businesses without adequate processes in place to manage those risks leave themselves vulnerable to exploitation by criminals.”

Bet365 was approached for comment.