Plausible deniability
The concept is tied up with the idea of a "paper trail", whereby journalists find evidence of orders or discussions between senior officials and agents doing the forbidden acts. Interceptions of phone messages or e-mail messages may also be evidence of wrongdoing by officials. If there is no definite evidence of wrongdoing by an official, then his/her denial can be taken as sincere. The denial is "plausible" (or,   at least, might be true). That achieves one of the main goals of public relations: for officials at least not to be caught red-handed doing something illegal. The effect of officials being caught red-handed can be extremely serious: see Watergate scandal.