Trump's CFO pleads guilty to tax evasion

A top executive at former President Donald Trump's family business has pleaded guilty to evading taxes in a deal that could potentially make him a star witness against the company at a fall trial.

Trump Organization CFO Allen Weisselberg pleaded guilty on Thursday to all 15 of the charges he faced in the case.

He was accused of dodging taxes on lavish fringe benefits he got from the company to the tune of $US1.7 million ($A2.4 million) over several years, including lease payments for a luxury car, rent for a Manhattan apartment and private school tuition for his grandchildren.

Weisselberg is the only person to face criminal charges so far in the Manhattan district attorney's long-running investigation of the company's business practices.

Judge Juan Manuel Merchan agreed to sentence Weisselberg to five months incarceration and five years probation at New York City's Rikers Island jail complex, although he will be eligible for release much earlier if he behaves well behind bars. The judge said Weisselberg will have to pay nearly $US2 million ($A2.9 million) in taxes, penalties and interest.

The plea bargain also requires Weisselberg to testify truthfully as a prosecution witness when the Trump Organization goes on trial in October on related charges. The company is accused of helping Weisselberg and other executives avoid income taxes by failing to accurately report their full compensation to the government.

Trump himself is not charged in the case.

Testimony by Weisselberg could potentially weaken the Trump Organization's defence. If convicted, the company could face fines or potentially be placed on probation and be forced to change certain business practices.