"False testimony" refers to the act of providing dishonest or untrue statements under oath or in a legal setting, with the intention to deceive or mislead others. Full definition
Unfortunately for the brother, he had given false testimony in a deposition that was taken concerning his knowledge of his relationship to his mother during the earlier part of the case. (indianainjuryblog.com)
I fired him the day before for providing false testimony to the Japanese police. (treehugger.com)
It also helps to prevent the investigator from delivering false testimony later. (slaw.ca)