Jared Kushner's lawyer failed to give the U.S. Senate Judiciary Committee documents President Donald Trump's son-in-law and senior adviser received about a "Russian backdoor overture and dinner invite," the committee's leaders said on Thursday.

In a letter to Kushner's attorney, Abbe Lowell, Sens. Chuck Grassley and Dianne Feinstein, the Judiciary Committee's Republican chairman and top Democrat, listed the documents and emails among materials Lowell has failed to produce.

Kushner, the letter said, also forwarded to an unidentified campaign adviser emails from September 2016 concerning Wikileaks, the whistle-blower group that published emails U.S. intelligence agencies determined Russian military intelligence had hacked from Democratic Party accounts.