Republican Presidential nominee Donald Trump has allegedly used $A72,000 of campaign donations to purchase thousands of copies of his own book.

The Daily Beast claimed the billionaire used the money to buy more than 3500 copies of the hardcover version of Crippled America: How to Make America Great Again, or nearly 5000 copies of the renamed paperback release, Great Again: How to Fix Our Crippled America.

Mr Trump’s campaign spokesperson said the books were bought “as part of gifting at the [Republican National] Convention”. Delegates received tote bags containing Crippled America at the event.

It would be illegal if Mr Trump accepted royalties for the sales, Federal Electoral Committee rules stated, but it was unknown if he had.

The book-buying frenzy was just the latest purchase by Mr Trump’s campaign that drew the ire of the United States media.

During his long campaign, Mr Trump has been questioned about numerous transactions using donation money – and his own – that have benefited his businesses greatly.

Trump Tower rent skyrockets as donors foot the bill

Up until March 2016, Mr Trump paid rent on Trump Tower (which he owns) from his own pocket. He has campaign staff based at the New York tower.

Mr Trump pays rent on Trump Tower with Republican donations. Photo: Getty

But in July he struck a deal with the Republican Party regarding the use of donor funds. It meant donor money paid for more of Mr Trump’s campaign.

Trump Tower rent nearly quintupled at the same time as donors began to pay for the Trump campaign to rent it, the Huffington Post reported.

When Mr Trump paid rent himself, it cost $A46,500 per month. Once donors took over it soared to $A221,500 per month.

Since this was revealed, the Trump campaign has said the extra money was spent on expanding office space, and that rent is not always paid monthly.

Trump flies Trump

Mr Trump flies in his private jet – emblazoned with his name – to campaign across the US. He uses a company called TAG Air to do it.

He has spent $A7.34 million with TAG Air during the campaign, The Washington Post reported.

And you guessed it, Mr Trump owns TAG Air.

Republican Party funding – from donors and Mr Trump – pays for the billionaire’s jet travel. Photo: Getty

Trump stays at Trump hotels

Mr Trump and his campaign have spent a whopping $A525,000 on accommodation and other services at his Mar-a-Lago resort in Florida.

This is on top of almost $A265,000 at other Trump properties and resorts around the US.

Mr Trump has said he will not take a salary if he is elected President.

For the hotel stays and aircraft use it is unclear what percentage of Mr Trump’s money and donor money has been used.

Mr Trump’s Mar-a-Lago Resort hosts campaign events and staff. Photo: Getty