Sen. Lindsey Graham, RS.C., testified Tuesday before a Georgia grand jury investigating possible interference in the 2020 presidential election, a source familiar with the planning confirmed to NBC News.

Graham’s testimony was expected to begin at 9 a.m. ET. He left the courthouse more than two hours after he arrived, the source said.

It is unclear if he answered any of the jury’s questions. NBC News has contacted Graham’s attorneys and his Senate office for comment.

Earlier this month, the Supreme Court denied Graham’s request to vacate a grand jury subpoena in the Georgia investigation. Fulton County District Attorney Fani Willis, who is leading the investigation, is seeking details about phone calls Graham made to top election officials in Georgia amid disproved allegations by then-President Donald Trump about widespread voter fraud in the 2020 elections.

The Supreme Court ruling allowed the grand jury subpoena to be enforced, but Graham could refuse to answer questions citing his right not to incriminate himself under the Fifth Amendment of the Constitution.

Graham had argued that he should not have to offer testimony on the calls because it was part of his pre-vote duties by Congress to certify the election results, and therefore the subpoena violates the speech or debate clause of the Constitution. that protects legislators from investigations into comments they make on their official duties.

Willis’s office is investigating a pair of post-election phone calls Graham made to Secretary of State Brad Raffensperger and his staff. Raffensperger, a Republican targeted by Trump and his allies, alleged that Graham suggested that he had the authority to disallow certain legally cast ballots. Graham denied making any such suggestion and said he was trying to understand the state’s process for verifying ballot signatures.