USviewer: "At this point we know less than a fraction of what the FBI knows," U.S. Representative Adam Schiff told reporters after Comey briefed the Republican-led committee.
On Wednesday, Schiff said the committee would investigate allegations of collusion between Republican Donald Trump's 2016 presidential campaign and Russia as part of its probe into allegations of Russian meddling in the election.
But he said the FBI had yet to give the panel a full intelligence briefing and they will call Comey back.
"There were very large areas that were walled off, and those walls are going to have to come down if we are going to do our job,” Schiff said.
The FBI did not immediately return a request for comment on Schiff's remarks.
Committee members questioned Comey for more than three hours about the scope of the FBI investigations and any individuals who may be the subject of any counterterrorism investigation, Schiff said.
"The director declined to answer those questions. It was unclear whether that was a decision he was making on his own or a decision that he is making in consultation with the Department of Justice," Schiff said.
U.S. intelligence analysts have concluded that Russia tried to help Trump win the White House in November by discrediting Democratic presidential nominee Hillary Clinton and her party through cyber attacks.
Appointed director of the Federal Bureau of Investigation by Democratic former President Barack Obama in 2013, Comey became the center of controversy during the presidential campaign over his handling of an inquiry into Clinton's use of a private computer server for government business while she was secretary of state from 2009-13.
The White House has dismissed the controversy over ties to Russia as a scam perpetrated by sore losing Democrats. Moscow has denied the claims.
Many Democrats said Comey's decision to disclose that the FBI was examining a new trove of Clinton emails 11 days before the Nov. 8 vote helped hand Trump a victory. Comey has stayed on as FBI director under Trump.
Trump fired his first national security adviser, Michael Flynn, after it emerged that Flynn misled Vice President Mike Pence over contacts Flynn had with the Russian ambassador before Trump took office on Jan. 20.
The Republican chairman of the committee, Representative Devin Nunes, told reporters there was still no evidence about any other contacts between Russian officials and the Trump campaign.