Story highlights Collins said she thinks Trump was unaware of the independence that an FBI director should be afforded

She said she believed Comey was truthful

Washington (CNN) Sen. Susan Collins said Sunday on CNN's "State of the Union" that she does not understand why President Donald Trump has refused to give a "straight yes or no" answer to questions about whether he secretly recorded his discussions with FBI Director James Comey.

The Maine Republican added that if any audio recordings do exist, she expected Trump to provide them to federal investigators looking into Russia's efforts to influence the 2016 election, saying if he did not, he should be legally compelled to do so.

"He should give a straight yes or no," Collins told anchor Brianna Keilar. "And he should voluntarily turn them over. ... I don't understand why the President just doesn't clear this matter up once and for all."

Comey was leading the FBI's investigation into Russian meddling in the US election when Trump fired him last month.

Collins also said she thought Department of Justice special counsel Robert Mueller, who now leads the Russia probe, would be more likely than Congress to compel the release of any audio recordings.

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