The top Democrat on the House Intelligence Committee on Thursday detailed a list of witnesses and documents Democrats say Republicans have kept them from accessing during the panel's Russia investigation, and he blamed the committee's chairman and House Speaker Paul D. Ryan (R-Wis.) for attempting to end the probe before it is complete.

Rep. Adam B. Schiff (D-Calif.) said committee Republicans had blocked Democrats' efforts to subpoena Deutsche Bank for financial records related to President Trump's family on the suspicion that Russians "may have laundered money through Trump properties." Democrats also were stymied in their effort to subpoena executives at Twitter, Schiff said, to secure the direct messages that members of Trump's inner circle exchanged with representatives of WikiLeaks and its founder, Julian Assange, who Democrats believe acted as Russian intermediaries during the 2016 presidential campaign.

Schiff complained that Republicans were unwilling to press those members of the Trump team who participated in a June 2016 meeting at Trump Tower for a complete record of their communications over email, telephone and encrypted applications. Then-campaign manager Paul Manafort, Trump's son-in-law Jared Kushner and son Donald Trump Jr. attended the meeting, which was initially billed to Trump Jr. as a means of securing information damaging to Trump's political opponent, Democrat Hillary Clinton.

According to two people with knowledge of the materials, the phone records Trump Jr. turned over to the panel were heavily redacted. Schiff added that GOP leaders refused to seek testimony from additional witnesses with knowledge of the Trump Tower meeting, including Russian lawyer Natalia Veselnitskaya and the president's daughter and adviser Ivanka Trump.

"If there's credible information that Ivanka Trump had contact with any participants in that meeting at the time of that meeting . . . I think it would be valuable to have her come and testify before the committee," Schiff said.

He added that he believes the committee should invite former White House chief strategist Stephen K. Bannon to testify, saying "it's my expectation that he will be doing so."

In a new book, author Michael Wolff writes that Bannon thought the Trump Tower meeting was "treasonous."

Schiff's complaints come as the House GOP begins to pivot its attention away from questions of possible Russian collusion and toward those about the FBI's conduct during its probes of Trump's alleged Russia ties and Clinton's use of a private email server while she was secretary of state. The phenomenon has inspired Democrats across Congress to strike out on their own, drafting reports and publicizing findings to date from the various Russia probes underway in the House and Senate.

Several Republican members of the House Intelligence panel have said in recent weeks they are eager to end the Russia investigation and issue a report, claiming they have nearly exhausted the roster of individuals they could interview.

Schiff said Thursday that the committee has interviewed 56 witnesses — half the number of people that have appeared before the Senate Intelligence Committee, Schiff said, meaning there are "dozens" of witnesses they have yet to bring in.

He blamed panel chairman Devin Nunes (R-Calif.) for ruling against bringing in certain witnesses, "even when he recused himself" from running the committee's probe. Nunes had deputized Rep. K. Michael Conaway (R-Tex.) to run the Russia probe while the House Ethics Committee investigated allegations that Nunes had improperly publicized classified information; he was cleared of those allegations in December.

A spokesman for Nunes declined to comment.

Schiff also said that he would hold Ryan responsible if the House probe "is prematurely curtailed for political reasons."

Ryan's spokeswoman, AshLee Strong, responded in a statement: "While Mr. Schiff tries to distract from the serious, bipartisan review that's been underway for nearly a year, we will stay focused on following the facts and working to safeguard the upcoming election."

Correction: A previous version of this story incorrectly attributed a statement to House Speaker Paul D. Ryan. The statement was from his spokeswoman.