Republican Sens. Chuck Grassley Charles (Chuck) Ernest GrassleySenate Republicans signal openness to working with Biden Senators offer disaster tax relief bill Trump spikes political football with return of Big Ten season MORE (Iowa) and Ron Johnson Ronald (Ron) Harold JohnsonGOP senator blocks Schumer resolution aimed at Biden probe as tensions run high The Hill's 12:30 Report - Presented by Facebook - Big 10 votes to resume football season GOP votes to authorize subpoenas, depositions in Obama-era probe MORE (Wis.) are requesting details on the travel records for former Vice President Joe Biden Joe BidenThe Memo: Warning signs flash for Trump on debates Senate Republicans signal openness to working with Biden National postal mail handlers union endorses Biden MORE's son Hunter Biden as they turn their focus past the impeachment trial.

Grassley and Johnson — the chairmen of the Senate Finance and Homeland Security and Governmental Affairs committees, respectively — sent a letter to Secret Service Director James Murray saying they were requesting the documents as part of a probe into "potential conflicts of interest posed by the business activities of Hunter Biden and his associates during the Obama administration."

"We write to request information about whether Hunter Biden used government-sponsored travel to help conduct private business, to include his work for Rosemont Seneca and related entities in China and Ukraine," the two senators added.

ADVERTISEMENT

As part of their request, the senators specifically want to know what sort of security detail Hunter Biden received while his father served as vice president, and a list of all dates and places Hunter Biden traveled with a protective detail.

They specifically want to know if he traveled on Air Force One or Air Force Two, the presidential and vice presidential aircraft, or on another government aircraft and whether additional family members were present for each trip.

The letter is the latest signal from Senate Republicans that they will step up their efforts to probe the Bidens, who have emerged as a top target for President Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE and his allies as Joe Biden seeks the Democratic presidential nomination this year.

Senate Judiciary Committee Chairman Lindsey Graham Lindsey Olin GrahamSenate Republicans signal openness to working with Biden Loeffler calls for hearing in wake of Netflix's 'Cuties' Quinnipiac poll shows Graham, Harrison tied in South Carolina Senate race MORE (R-S.C.) has also pledged to do oversight of Hunter Biden.

Trump's efforts to get Ukraine to launch investigations into his political rivals, including the Bidens, were at the center of the monthslong impeachment effort that ended in the Senate on Wednesday.

ADVERTISEMENT

Congressional investigators focused on Trump’s decision to delay Ukraine aid, which was eventually released in September, and a July 25, 2019 phone call with Ukrainian President Volodymyr Zelensky during which Trump asked Zelensky to work with his personal attorney Rudy Giuliani Rudy GiulianiJuan Williams: Breaking down the debates Giuliani criticizes NYC leadership: 'They're killing this city' More than 160 executives critique de Blasio's leadership amid pandemic MORE to “look into” the Bidens.



Republicans have targeted Hunter Biden over his time serving on the board of Ukrainian energy company Burisma while his father served as vice president.

In 2016, Joe Biden pushed for the dismissal of Ukrainian Prosecutor General Viktor Shokin because of concerns he was overlooking corruption in his own office, though Trump and his GOP allies have sought to tie the move to Hunter Biden's business interests.

Fact-checkers have debunked GOP claims that Joe Biden was acting with his son's interest in mind, and the former vice president has denied wrongdoing.

Kurt Volker Kurt VolkerGOP senators request details on Hunter Biden's travel for probe Yovanovitch retires from State Department: reports Live coverage: Senators enter second day of questions in impeachment trial MORE, the former U.S. envoy to Ukraine, told House lawmakers in November that Biden "was representing U.S. policy at the time" when he called for the prosecutor's dismissal.