Syria's Bashar al-Assad and his family are likely worth $1-2 billion, according to a recently published State Department report. 

The department said in a report mandated by Congress that it could only provide an "inexact estimate" on the Assad family worth based on publicly-available information.

It pointed to a number of difficulties in properly estimating the Assad family net worth, including assets that are spread across and concealed in a multitude of bank accounts, as well as assets hidden in real estate investments, corporations and offshore tax havens.

The Assads have further used false names and other individuals to obscure any off-shore assets they hold in an effort to evade US and international sanctions, the report published on Thursday said.

"The Assad family runs a complex patronage system including shell companies and corporate facades that serves as a tool for the regime to access financial resources via seemingly legitimate corporate structures and non-profit entities, and launder money acquired from illicit economic activities," it said.

That includes smuggling, arms trading, drug trafficking, and protection and extortion rackets, according to the department./agencies