Techniques include wire transfers to offshore bank accounts, investments in shell companies or deposits in cash businesses, and buying foreign currencies or (to a small extent) cryptocurrencies. In addition, the straightforward physical transportation of cash across national borders is an often-used method known as a “bulk cash transfer”.

The China-based investor contacts an individual who has US dollars available to sell in the United States. This seller of US dollars provides identifying information for a bank account in China, with instructions for the investor to deposit Chinese currency (renminbi) in that account. Once the owner of the account sees the deposit, an equivalent amount of US dollars is released to the buyer in the United States.

It’s a misconception that everyone who makes a lot of money in drugs or other illegal business makes an effort to launder their money. My brother and I held much of what we earned in cash. We knew the government could eventually take everything [else].

In our study of money laundering strategies used by people involved in the illicit drug trade in the UK and US, we found that street dealers do not typically undertake sophisticated laundering processes. Rather, they spend their cash on food and other routine living expenses.

Some dealers solicit close friends or family members to act as “strawmen”. These are people willing to put assets paid for by illicit drug money – such as cars, properties or even businesses – in their names on behalf of the dealer.

Along with bars, clubs and salons, construction companies and restaurants stand out as other cash-intensive businesses with high volumes of transactions – characteristics that make good fronts for laundering money.