Since the intelligence agencies’ report on Friday that President Vladimir V. Putin of Russia had ordered the hacking and leaks of Democratic emails in order to hurt Mrs. Clinton and help Mr. Trump, the president-elect and his aides have said that Democrats are trying to mar his election victory. Mr. Trump never completed any major deals in Russia, though he discussed them for years. The former British intelligence officer who gathered the material about Mr. Trump is considered a competent and reliable operative with extensive experience in Russia, American officials said. Mr. Wyden, trying to draw Mr. Comey out on information he may have heard during a classified briefing, asked whether the F.B.I. had investigated the Trump campaign’s contacts with Russia. Mr. Wyden kept pressing, asking Mr. Comey to provide a written answer to the question before Mr. Trump’s inauguration on Jan. 20, because he feared there would be no declassification of the information once Mr. Trump took office.