(CNN) More than one-fifth of the $3.9 million that President Donald Trump's 2020 re-election campaign has spent this year has gone to legal fees, the campaign's latest quarterly Federal Election Commission filing shows.

About $835,000 in payments for "legal consulting" were made to eight firms and the Trump Corporation, with the most -- $347,000 -- going to Jones Day. Another $185,000 went to the firm Larocca Hornik Rosen Greenberg & Blaha. About $24,000 went to the Trump Corporation.

The steep legal bills come amid a probe into whether the Trump campaign was involved in Russia's interference in the 2016 presidential election as well as a legal battle with adult film star Stormy Daniels.

In the first two months of 2018, the campaign paid $93,181.25 to the firm of Charles Harder, the attorney representing Trump in the Stormy Daniels case.

Trump's campaign raised $10.1 million in 2018's first three months and has $28.3 million in the bank, the campaign finance report shows.

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