(CNN) -- President Donald Trump's former national security adviser Michael Flynn handed over more than 600 pages of documents to the Senate intelligence committee, according to a source familiar with the matter.

The source says the documents are mostly business records, but they also include some personal documents "based on the narrowed requests from the committee."

The documents are in response to two subpoenas that the committee sent to Flynn businesses after the former national security adviser invoked his Fifth Amendment rights and decided not to comply with a separate subpoena asking for records about meetings and communications with Russian officials.

The committee had set a Tuesday deadline for Flynn to comply with the subpoena.

Flynn, along with former Trump adviser Michael Cohen, has also been subpoenaed by the House intelligence committee, which is conducting a separate probe into Russia's election meddling.

Flynn is expected to be at the heart of former FBI Director James Comey's testimony before the Senate committee Thursday.

Comey has alleged in memos that Trump had urged him earlier this year to drop the FBI investigation into Flynn, and senators are eager to hear from Comey about what exactly Trump said to him.

Trump has said that the Russia investigation played a role in his decision to fire Comey.

The Senate intelligence panel is also expected to call Flynn as a witness in its investigation.

Senate Intelligence Chairman Richard Burr, a North Carolina Republican, said the committee has ruled out considering Flynn's request for immunity to testify before the committee.

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