The Australian Taxation Office has hit one of Australia's wealthiest people with a $242 million tax bill, following an extensive audit of financial affairs of high net worth individuals, according to The Australian newspaper.

The bill, which includes tax and penalties, relates to several years of activity and the person's use of an offshore tax haven. The tax office audited the person, who has not been identified, as part of its focus on wealthy individuals.

The report comes as tax authorities around the world – such as the US Internal Revenue Service – are chasing down wealthy citizens they suspect of holding undeclared funds in offshore accounts.  

The newspaper said the ATO audits people whose financial dealings may be of interest using a range of compliance activities – including data matching, profiling and investigating "third party" information, such as media reports.

The $242 million tax bill represents one-sixth of the $1.5 billion previously raised since the tax office set up its high-wealth individual taskforce 14 years ago.

A high-wealth individual is defined as someone who controls more than $30 million in net wealth.

The tax office is ramping up its monitoring of wealthy Australians this financial year and is set to audit 120 high-wealth Australians and conduct 420 reviews. The figure is up from last financial year, when 28 people were audited and 936 reviews were undertaken, the publication said.