The False Statements Act makes it a crime to “knowingly and willfully” give a false statement – written or verbal – to the federal government for a broad range of investigative or administrative matters. The falsehood must be relevant to the matter at hand, and the crime generally carries a sentence of up to five years, although it can be longer in certain circumstances.
Giving a false statement is a different crime than committing perjury – the act of lying under oath – even though the sentences and standards for conviction are similar.
http://checkyourfact.com/2017/07/27/fact-check-is-it-illegal-to-lie-to-congress-even-when-youre-not-under-oath/