Kevin Johnson

USA TODAY

WASHINGTON — House Democratic leaders are asking the FBI to investigate whether Republican presidential nominee Donald Trump worked in concert with the Russian government in the recent cyber-attacks against the Democratic National Committee.

Referring to Trump's comments last month urging Russia to unearth Democratic nominee Hillary Clinton's deleted emails, the ranking members of four key House committees called on FBI Director James Comey to "assess whether connections between Trump campaign officials and Russian interests may have contributed to these attacks."

"It is critical for the American public to know whether those actions may have directly caused or indirectly motivated attacks against Democratic institutions and our fundamental election process,'' the House members wrote in Tuesday letter to Comey posted on Medium.

The members who signed the letter are Reps. Elijah Cummings of the Oversight and Government Reform Committee; John Conyers of the Judiciary Committee; Elliot Engel of the Foreign Affairs Committee; and Bennie Thompson of the Homeland Security Committee.

The FBI has been investigating Russia's ties to the hack, which resulted in the leak of thousands of pages of documents on the eve of last month's Democratic National Convention.

The documents revealed apparent attempts by party officials to provide Clinton an advantage during her heated primary battle with Vermont Sen. Bernie Sanders. The embarrassing disclosures ultimately prompted the resignation of DNC Chairwoman Debbie Wasserman Schultz.

The Trump campaign did not immediately respond to a request for comment.

FBI to make Clinton documents public in coming days