Wiktionary
barefaced lie
n. A falsehood told with utter confidence and without trying to conceal the fact that it is false, especially a planned or deliberate falsehood.
Usage examples of "barefaced lie".
Yatakangi optimisation programme as quote a barefaced lie unquote.
He had counted on getting from her, at a minimum, a hint as to where the path either entered the thicket or left it, and all he had got was a barefaced lie with Sumner Hoff to back it up.
Normally she would have laughed back at him, since they both knew he had just told a barefaced lie.