One-time advisor of U.S. president-elect Donald Trump Carter Page addresses the audience during a presentation in Moscow, Russia, December 12, 2016. Sergei Karpukhin/Reuters The Senate Intelligence Committee has so far had a hard time getting key witnesses to comply with its investigation into Russia's interference in the 2016 election — and whether President Donald Trump's campaign team was at all involved.

Former national security adviser Michael Flynn will reportedly invoke his Fifth Amendment right and decline a subpoena issued by the committee for documents related to his interactions with Russian officials between June 2015 and January 2017. And Carter Page, an early foreign policy adviser to Trump's campaign team, has so far declined to provide the committee with similar documents.

Flynn's lawyer, Robert Kelner, did not respond to request for comment on Monday. But Page said Monday that the committee has not yet subpoenaed anything from him, as they have Flynn. He added that he has "no intention to plead the Fifth, since I've never done anything wrong."

Andrew Wright, an associate professor at Savannah Law School who specializes in federal criminal law and national security, said Flynn's plan to invoke his Fifth Amendment rights against self-incrimination "will not play well publicly because many in Congress, the media, and the public will interpret it as an admission of guilt.

"However, there are good reasons for Flynn’s lawyer to recommend an assertion of privilege whether he is guilty of a crime or not," Wright said.

The Senate Intelligence Committee sent a letter to Page on April 28, a copy of which Page provided to Business Insider, asking him to provide extensive information about any contact he had with Russian officials or representatives of Russian business interests since June 2015.

Page volunteered to be interviewed by the committee in March. But he said earlier this month that the committee's requests were "groundless," "outrageous," and "would cover redundant, highly irrelevant information collected in further violation of my civil rights given the unjustified FISA warrants which already targeted me last year."

Page said Monday that he does not expect the committee to issue him a subpoena.

"After the severe intrusions against civil liberties by the Clinton/Obama regime which disgraced our Constitution and came up with nothing last year, it seems unlikely that the Congress will continue these authoritarian tactics that would represent a further affront to our democracy," he told Business Insider.

The FBI obtained a warrant under the Foreign Intelligence Surveillance Act last summer to monitor Page's communications, The Washington Post reported in April. The bureau is reportedly investigating Page's trips to Moscow and contact with at least one Russian official last year.

The Senate also asked Page for information about any financial holdings he had in Russia between June of 2015 and January of 2017. Page's ties to Russia include investments in Russia's state-owned oil giant Gazprom.

Page said he would still cooperate with the committee’s investigation "in the form of a future open testimony." But Sens. Richard Burr and Mark Warner, the chairman and ranking member of the Senate Intelligence Committee, respectively, said in a joint statement earlier this month that "the committee will consider its next steps" if Page does not provide the requested materials by listed deadlines.

"Mr. Page has indicated in correspondence to the Committee that he looks forward to working with us on the matter, and that our cooperation will help resolve what he claims are false allegations," Burr and Warner wrote. "For that to happen, Mr. Page must supply the requested documents to the Committee."