Donald Trump used $258,000 from his charitable foundation in the settlement of legal disputes concerning his own personal businesses, according to The Washington Post.

Funds from the Donald J. Trump Foundation were reportedly directed to cover unpaid fines from the town of Palm Beach, Florida and arising from a lawsuit over a hole-in-one at a charity tournament held at a Trump golf course in New York.

The Florida case saw the Republican US presidential candidate's Mar-a-Lago resort hit with a $120,000 fine for having a flagpole that was close to double the regulation height. As part of that settlement, the paper reported that $125,000 from the Trump Foundation – which is chiefly funded by third party donors as opposed to Trump himself – was donated to veterans' charities.

The Washington Post claims that the cash for a further $158,000 settlement came from Trump's foundation, this time in relation to a 2010 case where a golfer was denied prize money of $1m for a hole-in-one.

The latest report comes from journalist David Fahrenthold and, if found to be true and without a legitimate excuse (with Trump's camp declining to comment thus far), it would represent the biggest abuse by Trump of US tax laws.

Two weeks ago, Fahrenthold raised questions over purchases Trump made using money that had been donated to the charity. Such payments could potentially violate IRS rules against self-dealing.

New York's attorney general, Eric T Schneiderman, announced earlier this month that his office was investigating Trump's foundation. He said it was seeking to determine whether a political donation it had made in support of the Florida attorney general was in compliance with state laws.

Schneiderman told CNN at the time:

"We have been concerned that the Trump Foundation may have engaged in some improprieties."