From The Arthashastra:
Just as it is impossible to know when a swimming fish is drinking water, so it is impossible to find out when a government servant is stealing money
From Kautilya (c. 4th century BCE), Indian teacher, philosopher, economist, jurist and royal advisor, The Arthashastra:
Just as it is impossible to know when a swimming fish is drinking water, so it is impossible to find out when a government servant is stealing money