The three wise monkeys are a pictorial maxim that together embody the proverbial principle “see no evil, hear no evil, speak no evil”.
(The three monkeys – of Japanese origin – are Mizaru, covering his eyes, who sees no evil; Kikazaru, covering his ears, who hears no evil; and Iwazaru, covering his mouth, who speaks no evil.)
There are various meanings ascribed to proverb including associations with being of good mind, speech and action.
However, the image/proverb can in fact refer to a lack of moral responsibility on the part of people who refuse to acknowledge wrongdoing — they look the other way, turn a blind eye, pretent not to know.
Turning a blind eye — an idiom describing the ignoring of undesirable information.
Bury one’s head in the sand — an idiom describing the act of ignoring or hiding from danger/unplesant realities.