UPDATE 14-Trump Organization, CFO are charged in 'sweeping' 15-year tax fraud

(Adds statement from CFO's lawyers, comment from lawyer not involved in case, background)

By Karen Freifeld, Jonathan Stempel and Jan Wolfe

NEW YORK, July 1 (Reuters) - Donald Trump's namesake company and longtime financial chief pleaded not guilty on Thursday to what a New York prosecutor called a "sweeping and audacious" tax fraud, arising from a probe into the former U.S. president's business and its practices.

The indictment against the Trump Organization and its chief financial officer Allen Weisselberg is the first in a nearly three-year investigation by Manhattan District Attorney Cyrus Vance, which New York Attorney General Letitia James joined in May.

It could undermine the Trump Organization's relationships with banks and business partners, and complicate Trump's political future as the Republican resumes addressing rallies and mulls a 2024 White House run.

Trump himself has not been charged, and renewed his claim that the probe was a political "witch hunt." Vance and James are Democrats.

Prosecutors accused the Trump Organization and Weisselberg of having since 2005 defrauded tax authorities by awarding "off the books" benefits to company executives.

Weisselberg, 73, was charged with concealing $1.76 million of income, including rent for a Manhattan apartment, lease payments for two Mercedes-Benz vehicles and tuition for family members, with Trump signing checks for the tuition himself.

Prosecutors said this enabled Weisselberg, who has worked for Trump for about 48 years, to evade roughly $900,000 in taxes and collect $133,000 in refunds he did not deserve.

"To put it bluntly, this was a sweeping and audacious illegal payments scheme," Assistant District Attorney Carey Dunne said at the defendants' arraignment in Manhattan Criminal Court. "This is not a standard practice in the business community, nor was it the act of a rogue or isolated employee."

The 15-count indictment charged the defendants with scheming to defraud, tax fraud and falsifying business records.

Weisselberg was also charged with grand larceny, which carries a maximum 15-year prison term. The Trump Organization could face fines and other penalties if convicted.

"If the allegations in the indictment are true, this was pants-on-fire tax evasion," said Daniel Hemel, a tax law professor at the University of Chicago. "It is very hard to believe that this could have happened without the man on top knowing."

'WITCH HUNT'

Thursday's charges could increase pressure on Weisselberg to cooperate with prosecutors, which could be crucial to any future case against the former president.