Mexican President Felipe Calderon signed a new law on Tuesday to crack down on money laundering, which a minister estimated at around $10 billion per year.
Congress passed legislation last week to allow law enforcement authorities to better monitor suspicious cash purchases of assets such as homes, cars and jewelry.
The new law provides tools to prevent drug cartels from boosting their coffers to "finance more crime, corrupt authorities or violate the rights of citizens," Calderon said as he signed the bill.
Mexican Finance Minister Jose Antonio Meade told reporters that various sources estimate that money laundering was "in the neighborhood of $10 billion" per year.
The US State Department estimates that between $19 billion and $39 billion are laundered in Mexico every year.
The new law requires businesses to report the buying or selling of real estate worth over one million pesos ($77,000); planes, boats or cars worth over 200,000 pesos ($15,000); and jewelry, watches and works of art worth more than 300,000 pesos ($23,000).
Calderon, who leaves office in December, launched a major offensive against the country's powerful drug cartels in 2006. An estimated 60,000 people have been killed in drug-related violence since then.