A new investigation has revealed Republican nominee Donald Trump used more than $258,000 (£198,660) from his charitable foundation to settle lawsuits involving his for-profit businesses. The findings may provide evidence that Trump may have violated laws which prohibit individuals from using nonprofit money to help themselves in other businesses.

According to the Washington Post report, four newly documented expenditures provide evidence of Trump's alleged wrongdoing. In all instances, Trump used funds from his charitable foundation which is funded almost in its entirety by other individuals' money.

In one case, Trump's Mar-a-Lago Club faced $120,000 (£92,388) in unpaid fines to the town of Palm Beach, Florida. The club settled with the town, which waived the fines if the club made a $100,000 (£76,990) donation to a charity for veterans. Trump, however, sent a check from the Donald J Trump Foundation to the charity, tax records show.

In another, court documents show one of Trump's New York golf courses settled a lawsuit by making a donation to the plaintiff's chosen charity. Tax records reveal the Trump Foundation made a $158,000 (£121,644) donation to the chosen charity.

The Washington Post found other situations in which smaller amounts were involved. Trump used $5,000 (£3,849) of the foundation's money in 2013 to purchase adverts for his hotel chain in programmes for three events by a DC preservation group. A year later, Trump used $10,000 (£7,699) of the foundation's money to buy a portrait of himself at a charity fundraiser. This would be the second portrait Trump purchased of himself using money from the foundation.

The GOP nominee could face penalty taxes or be forced to reimburse his foundation the money he spent on himself if the Internal Revenue Service (IRS) were to determine he violated self-dealing rules. The Post reported Trump is also being investigated by the New York attorney general's office for possible state charity law offenses.

The Trump Foundation has not received funding from Trump since 2009, records show. Pro-wrestling executives Vince and Linda McMahon, however, donated $5m (£3.8m) to the foundation from 2007 to 2009.

Trump's Democratic rival Hillary Clinton's campaign slammed Trump as "a fraud" over the report, ABC News reported. "Clearly the Trump Foundation is as much a charitable organisation as Trump University is an institute of higher education," Clinton deputy communications director Christina Reynolds said in a statement.

"Trump's vision of charity is taking money from others to settle his own legal issues...which experts say is a clear violation of laws governing charitable organisations," Reynolds continued.

An attorney who represents and advises nonprofits at a law firm in Washington DC told the Post that the situation was "really shocking". Jeffrey Tenenbaum said: "If he's using other people's money—run through his foundation—to satisfy his personal obligations, then that's about as blatant an example of self-dealing [as] I've seen in a while."

Trump's campaign has yet to respond to the allegations.