Senator John Curtis, a Republican from Utah, has asked the leaders of the Senate Judiciary Committee to open an investigation into the sons of US President Donald Trump and former President Joe Biden, citing the president's involvement in the cryptocurrency industry.

In a letter sent Monday to committee Chair Chuck Grassley and ranking member Dick Durbin, Curtis urged the panel to examine “the use of presidential family relationships for private financial benefit, preferential treatment, or access by domestic and foreign interest.” He also requested subpoenas for Donald Trump Jr. and Hunter Biden.

Curtis singled out Donald Trump Jr. for accepting gifts from Russian oligarch Umar Kremlev in connection with his wedding, for his “active promotion of family-backed cryptocurrency ventures,” and for advisory roles with prediction market platforms that fall under the regulatory purview of the Commodity Futures Trading Commission. Last week, the president said his son had repaid Kremlev for what Donald Trump Jr. and his wife called a “generous wedding gift.”

The Utah lawmaker called for a similar probe into Hunter Biden, citing his “substantial business with foreign entities” and instances in which either man's relationship to the presidency was “invoked or understood to provide value.” President Biden pardoned his son in December 2024 for crimes he “committed or may have committed or taken part in over the last decade.” Curtis noted that Hunter Biden had “denied involving his father in his business dealings.”

“The purpose of such an inquiry should be straightforward: establish the facts, determine whether existing ethics, disclosure, or anti-corruption laws apply, and identify reforms necessary to prevent the presidency from becoming a vehicle for private enrichment by those closest to it,” Curtis said.

The senator published the letter on his official Senate website (PDF) and announced it in a post on X.

Calls for an investigation into the Trump family's crypto ties are nothing new in the current session of Congress, but they have largely come from House and Senate Democrats. Lawmakers have asked authorities to probe potential conflicts of interest surrounding Trump's memecoin, his family's World Liberty Financial business, and a $500 million deal tied to Abu Dhabi's royal family.

Curtis is serving his first term in the Senate and will not be up for reelection until 2030. Because his request originates from the president's own party, it breaks from the pattern of earlier, largely Democratic-led efforts, and whether Grassley and Durbin act on the letter — including the proposed subpoenas — will determine whether the inquiry moves forward in the committee.

CLARITY Act still in limbo in the US Senate as midterm elections approach

The call for an investigation into Donald Trump Jr. and Hunter Biden came a week after Senate Republicans failed to secure enough support from Democrats to pass the Digital Asset Market Clarity Act, a bill expected to establish market structure rules for the crypto industry.

According to some Democrats, one of the sticking points for not supporting the bill was Trump “using crypto to turn the presidency into a profit generating machine.” The president disclosed that he had earned $1.4 billion from ventures tied to digital assets in 2025.

Republicans said the president had agreed to stronger ethics provisions in the bill affecting his crypto investments before the vote, but many Democrats argued the measures did not go far enough to prevent corruption. With midterm elections approaching and the president's digital asset earnings already a stated sticking point in the market structure debate, the proposed probe keeps congressional scrutiny of the president's crypto ventures on the Senate agenda alongside the stalled bill.