The Republican National Committee has paid nearly half a million dollars to a law firm representing former White House communications director Hope Hicks in the ongoing Russia investigation, Federal Election Commission records show.

The two payments in April, totaling $451,779, were made to Trout Cacheris & Janis for "legal and compliance services." Hicks is represented by the firm’s founder, Robert Trout. Two additional attorneys at the firm represent other witnesses in the Russia probe. The firm has also represented Bijan Kian, the one-time business partner of former national security adviser Michael Flynn.

In late February, Hicks appeared before the House Intelligence Committee for a closed-door interview related to Russia interference in the 2016 election but refused to answer questions about her time in the White House, according to Republicans and Democrats on the panel.

One of the few White House staffers who was at Trump's side since the early days of his campaign, Hicks faced questions about the campaign, transition and first year of the administration — including her role in the public statement issued by Donald Trump Jr. in July 2017 in response to a New York Times report last year about Trump Jr. and Jared Kushner's meeting with a Russian lawyer at Trump Tower in June 2016.

Hicks has also been interviewed by Special Counsel Robert Mueller's team over a two day period.

The RNC did not respond to a request for comment about whether the payments were for Hicks' legal fees. Hicks’ attorney Robert Trout declined to comment to ABC News. It's not clear whether the payments were for Hicks' legal fees, the other witnesses represented by the firm, or for other matters. Trout Cacheris & Janis did not respond to a request for comment about the payments.

The payments show a continuation of the growing legal fees that the Trump campaign and the Republican National Committee are paying.

“Legal fees are typically a small percentage of the overall cost of running a presidential campaign – usually around 5 percent of all the expenditures in the election cycle in which the election takes place,” said Brett Kappel, a veteran federal election lawyer.

The Trump campaign has spent nearly $228,000 to cover some of the legal expenses for President Trump's longtime attorney Michael Cohen, sources familiar with the payments told ABC News raising questions about whether the Trump campaign may have violated campaign finance laws.

Federal Election Commission records show three payments made from the Trump campaign to a firm representing Cohen beginning in 2017. The "legal consulting" payments were made to McDermott Will and Emery — a law firm where Cohen's attorney Stephen Ryan is a partner — between October 2017 and January 2018.

It was those three payments, sources tell ABC News, that were related to Cohen's legal defense.

The Trump campaign spent more than $830,000 on legal consulting during the first three months of 2018, including one payment to the firm representing Cohen, according to FEC reports. The payments made up more than 20 percent of the total campaign expenditures.

In 2017, the Trump campaign also paid legal fees to the attorneys representing top aides -- and family members -- tangled in the ongoing Russia probes.

The Trump campaign and the Republican National Committee paid $514,000 in legal fees for Donald Trump Jr. in 2017 and in January 2018, the Trump campaign paid more than $66,000 to the law firm representing former Trump bodyguard Keith Schiller, who has been a fixture at Trump's side for decades and served as Trump's director of Oval Office operations until September.

The Patriot Legal Defense Fund was established earlier this year to help former Trump campaign staffers and Trump administration officials pay for legal bills associated with the ongoing Russia probes.

It is unclear, however, who has benefited from the fund as it does not disclose its beneficiaries. It's also not clear now much money the fund currently has.

Trump and his immediate family members are excluded from receiving money from the fund, and a source close to Michael Flynn told ABC News in February that he would not accept support from the fund.