COMMENT | In recent years, a concept has gained traction as a means of investigating those with suspect cash and inexplicably high-value holdings.

It is called unexplained wealth. It refers to valuable assets belonging to officials – or others in positions of power and influence – that is clearly incommensurate with their publicly-declared earnings or known business interests.

The Organized Crime and Corruption Reporting Project (OCCRP), a global network of investigative journalists, has also produced a comprehensive description of unexplained wealth.

At the heart of the concept is a very simple mathematical formula, as described by the Western Australia Corruption and Crime Commission:

Unexplained wealth = Total wealth less lawfully acquired wealth...