What is the origin of the idiom "on the fiddle" and when to use it?

The origin of the idiom "on the fiddle" is believed to have originated in the mid-19th century in British English. It likely draws from the association of the violin (also called a fiddle) with trickery or manipulation, as well as the notion of playing a fraudulent tune. It is commonly used to discuss individuals who exploit loopholes, engage in tax evasion, commit fraud, or manipulate systems for personal gain.