Letter, written on March 7, says audit is in line with 'IRS's practice for large and complex businesses'

Instead he has published a letter from his tax attorneys which says he has been under audit for the past decade non-stop

Trump came under pressure this week to release his tax returns which he says he cannot do as he is being audited

Tax counsel for Republican presidential candidate Donald Trump said in a letter released Wednesday that the billionaire businessman has been under continuous IRS audit for more than a decade.

In the letter, released by the Trump campaign to demonstrate that the candidate is in fact under audit, Sheri Dillon and William Nelson wrote that Trump's personal federal tax returns 'have been under continuous examination by the Internal Revenue Service since 2002, consistent with the IRS's practice for large and complex businesses.'

Until now the only insight into his finances has been from a declaration made last year which listed his assets in value bands, with 28 placed at $25 million or above.

Not saying: Trump has cited the audits as the reason he refuses to release his tax returns for public examination.

With assets like these: Trump announced he was running for president at the Trump Tower in Manhattan, one of the properties which makes him a billionaire multiple times over

The Republican front-runner has parried calls for him to publish his tax returns for months. In contrast Ted Cruz and John Kasich have published limited versions of their tax returns.

The Trump attorneys said the examinations of returns for years 2002 to 2008 'have been closed administratively by agreement with the IRS without assessment or payment, on a net basis, of any deficiency,' while the examinations for the years 2009 and onward are 'ongoing.'

Trump has cited the audits as the reason he refuses to release his tax returns for public examination.

The release came as Trump was facing intense scrutiny for comments he'd made earlier in the day on abortion.

Trump said during a televised town hall taping that women should be punished for getting abortions if they are ever made illegal.

He later reversed himself, issuing a statement saying that abortion providers, not women, are the ones who should be held legally responsible.

The letter is dated March 7, more than three weeks ago.

The attorneys also wrote that Trump's personal federal income tax returns are 'inordinately large and complex for an individual' because of the nature of his business dealings.

THE LETTER: Donald Trump released this letter from his tax advisers after promising to do so during an MSNBC-hosted town hall broadcast