Adverb
in a mendacious and untruthful manner
Source: WordNetI told him, quite untruthfully, that I had just returned from leave Source: Internet
“From the start, when the enormity of what you had done and the likely consequences for you struck home, you untruthfully said to the paramedics and a police officer that someone must have thrown a firework into your shop.” Source: Internet
The bill actually requires that the physician state untruthfully on the death certificate that “the cause of death was the underlying terminal illness or condition of the patient.” Source: Internet