Tax leak reveals Trump paid $38 million in 2005

US President Donald Trump paid $38 million in taxes on more than $150 million in income in 2005, the White House acknowledged on Tuesday, as a handful of elusive details about the president's tax status were leaked to the US media.

MSNBC host Rachel Maddow said she received the documents from journalist David Cay Johnston, who said on her show that he received them in the mail.

The leak, a summary of one year's filing from more than a decade ago, is a small but tantalising glimpse into the mogul's tax history.

Trump has steadfastly refused to release his full tax returns, breaking with decades of tradition among presidential candidates of all political parties.

The returns, which MSNBC posted on its website, showed Trump paid an effective federal tax rate of 25% in 2005 after writing off $100 million in losses.

The White House said in a statement that Trump took into account "large scale depreciation for construction."

The snapshot was broadly favourable to the White House and appeared to back up Trump's claim that he paid his fair share of taxes.

However, the 2005 return showed amounts owed but, crucially, not sources of income that would confirm or repudiate questions about Trump's business ties.

"The documents show Trump and his wifem Melaniam paying $5.3 million in regular federal income tax -- a rate of less than 4%," Johnston wrote in a post on the Daily Beast.

"However, the Trumps paid an additional $31 million in the so-called 'alternative minimum tax,' or AMT."

AMT was originally designed to prevent rich taxpayers from using excessive loopholes, and Trump has previously called for its elimination.

The White House said in a statement on Tuesday that Trump, as head of the Trump Organisation, had a responsibility "to pay no more tax than legally required."

Presidents and major candidates for the White House have routinely released their income tax returns.

Trump says he has not released his tax returns because they are under audit by the Internal Revenue Service. Experts say an IRS audit does not bar someone from releasing the documents.