Eric Trump's charity isn't the first in the family to come under scrutiny

— -- Eric Trump is not the first member of the first family to have his eponymous charitable foundation scrutinized.

The operations of President Donald Trump's own foundation were discussed during the 2016 campaign, and the extent -- or lack thereof -- of his contributions became a point of discussion for his opponents.

Now questions about how the Eric Trump Foundation operated and paid vendors -- including properties owned by his own father -- have been raised by a Forbes article published Tuesday.

Here is a breakdown of the Trump family foundations and their respective flashpoints.

How the Donald J. Trump Foundation got and gave money

Even though his name is the basis for the charity, Trump was never the biggest contributor, according to the organization's 990 forms for 2001 through 2014.

Trump made contributions to the foundation from 2001 until 2008, but he is not listed as making any financial contributions since then.

His contributions range from $713,000 in 2004 to $30,000 in 2008; his total contributions to his foundation are in excess of $2.7 million.

A variety of charities are listed as having received contributions from the foundation during those years. The William J. Clinton Foundation (the earlier name of the Clinton Foundation), the conservative Citizens United Foundation, and a number of police benevolent societies, athletic leagues and cancer charities were among the various recipients of money from the foundation. As recently as 2010, Trump's foundation donated to Clinton's.

What were the issues with Donald Trump's foundation?

The president's eponymous foundation remains under investigation by the New York State Office of the Attorney General.

"The foundation’s fundraising has been suspended since the attorney general issued a notice of violation last fall, and it cannot legally dissolve until our investigation is complete," press secretary Amy Spitalnick said in a statement to ABC News.

New York Attorney General Eric Schneiderman launched the investigation into Trump's foundation over a donation that was made to a political fundraising group associated with Florida Attorney General Pam Bondi.

Schneiderman's office shared a letter sent to Donald Trump, dated June 9, 2016, in which it said the Trump Foundation contributed to a political organization, which is against IRS rules.

The letter concerned a $25,000 payment made by the foundation to And Justice for All, the group associated with Bondi, who spoke at the Republican National Convention and endorsed Trump’s presidential run.

"In short, the contribution was made in error due to a case of mistaken identity involving organizations with the same name," Allen Weisselberg, the foundation's treasurer, responded in a June 28, 2016, letter.

Weisselberg said in the statement that the foundation "regrets the mistake" and said it "was an isolated incident." He said the foundation learned about the error in March after media reports, at which point it filed appropriate forms with the IRS and Trump paid a federal excise tax with a personal check.

The Trump campaign released a statement slamming the investigation as being politically motivated.

"Attorney General Eric Schneiderman is a partisan hack who has turned a blind eye to the Clinton Foundation for years and has endorsed Hillary Clinton for president. This is nothing more than another left-wing hit job designed to distract from crooked Hillary Clinton’s disastrous week," said Jason Miller, the campaign's senior communications adviser.

What is Eric Trump's foundation?

Trump's second-eldest son, Eric Trump, established a foundation to support St. Jude Children's Research Hospital, which focuses on childhood cancer and life-threatening diseases.

Eric Trump stopped all direct fundraising efforts for the foundation in December 2016, citing his father's election, and said that the separation would carry through the tenure of his father's presidency.

In a statement on the charity's website, it states that "the foundation is being restructured and renamed, and under new leadership, it will continue its mission to support St. Jude Children's Research Hospital in the fight against pediatric cancer."

What prompted the new round of scrutiny?

Forbes published an article Tuesday alleging that the Eric Trump Foundation had been using donations -- from donors who believed the money was going to St. Jude -- to pay the Trump Organization high sums for use of Trump properties during fundraisers and re-donating some funds to charities friendly with Trump interests.

The report stated that the Eric Trump Foundation paid the Trump family business hundreds of thousands of dollars over the last seven years for use of one of the organization’s golf courses, funds which he claimed were being donated nearly in full to the children’s cancer charity.

In a statement released Tuesday, a spokesman for the president's son defended the Eric Trump Foundation.

"During the past decade, the Eric Trump Foundation has raised over $16.3 million for St. Jude Children’s Research Hospital while maintaining an expense ratio of just 12.3 percent," the statement reads. "The Eric Trump Foundation was also responsible for building a $20 million dollar ICU which treats the sickest children anywhere in the world suffering from the most catastrophic terminal illnesses."

The statement continued: "Contrary to recent reports, at no time did the Trump Organization profit in any way from the foundation or any of its activities. While people can disagree on political issues, to infer malicious intent on a charity that has changed so many lives, is not only shameful but is truly disgusting. At the end of the day, the only people who lose are the children of St. Jude and other incredibly worthy causes."