Hillary Clinton's campaign appears not to have returned or donated to charity the more than $5,000 in contributions from the former co-owner of a website linked to underage prostitution and whose donations have backed a number of current and former Democratic politicians into a corner.

Controversy surrounding donations from the owners of Backpage.com, an online classified website that has come under fire from politicians including Sen. Kamala Harris (D., Calif.), has forced a number of politicians—particularly in the state of Arizona—to return or donate the tainted contributions.

Jim Larkin, a former co-owner of Backpage, gave a $5,400 contribution on July 26, 2016, to the Hillary Victory Fund, a joint fundraising effort between the Clinton campaign, the Democratic National Committee (DNC), and more than 30 state Democratic parties. The money was then transferred to Hillary for America, Clinton's campaign committee.

The campaign appears to have not returned the money to Larkin, a search of Federal Election Commission records shows.

A number of Democratic politicians in Arizona have come under fire as a result of the contributions they received from Backpage's former co-owners as their legal troubles began to mount.

The Arizona Republic published an investigative report in April that found Michael G. Lacey, the other co-owner of Backpage, donated $162,000 to Democratic politicians on the state and federal level in recent years.

Following the report, the Washington Free Beacon discovered one politician who received contributions from an owner that the publication had missed: David Garcia, the Democratic candidate for governor in the state. Garcia announced he would donate the money from his campaign to homeless youth and the victims of sex trafficking shortly after publication.

Other Democratic politicians in Arizona have done the same.

Former Democratic Congresswoman Ann Kirkpatrick, who is considering another run for the House of Representatives next year, announced this week that she is donating the contributions to the Arizona Coalition to End Sexual and Domestic Violence. Kirkpatrick dumped the donations months after other politicians in the state had given theirs away.

The controversy surrounding Backpage.com spilled over after Arizona State University partnered with the Phoenix Police Department and found that 80 percent of the postings on the adult section portion of the website involved prostitution. More than 900 ads were found in the Phoenix area alone, including advertisements for underage girls.

Backpage's practices caused the National Association of Attorneys General in 2013 to urge Congress to amend federal law to fight child sex trafficking and hold companies such as Backpage accountable.

The House of Representatives passed legislation in May 2014 to punish companies that knowingly advertise commercial sex acts involving a minor or gain benefit from such advertisements. Rep. Ann Wagner (R., Mo.), the bills cosponsor, referenced Backpage as a vehicle "for advertising the victims of the child sex trade to the world."

The United States Senate unanimously passed a resolution in 2016, spearheaded by Sen. Rob Portman (R., Ohio), to hold Backpage in contempt of Congress for not complying with a subpoena. The company refused to provide documents on how they were combating trafficking in their advertisements.

Carl Ferrer, the chief executive officer of the website, was arrested in October 2016. Arrest warrants for Larkin and Lacey were later issued that described them as "controlling shareholders" of Backpage.

At the time of the CEO's arrest, then-Attorney General Kamala Harris, now a senator who is considered a potential Democratic candidate for president in 2020, said the website was "purposely and unlawfully" designed as an online brothel.

Harris twice brought pimping charges against Ferrer, Larkin, and Lacey; those charges were dismissed. However, the men are being prosecuted on money laundering charges in the state of California for profiting on the ads that allegedly facilitate prostitution, Reason reported.

The three men, along with two other executives, in January appeared in front of the Senate Permanent Subcommittee on Investigations in Washington, D.C.

The subcommittee released a report stating that not only was the site hosting the ads, they were actively editing them to remove words in relation to underage trafficking, ABC News reported at the time.

Clinton's campaign and victory fund treasurers did not return requests for comment by press time.