CHICAGO (AP):

Thirty-two people from the United States and Mexico are accused of running a multistate gold-for-cash scheme that laundered more than $100 million in US profits for Mexico's powerful Sinaloa drug cartel, a complaint unsealed this week in federal court in Chicago said.

The cartel associates used cash from narcotics sales to purchase scrap and fine gold - including from Chicago-area jewellers - then send it to metal refineries in Florida and California; plants sometimes transfer payments for the gold directly to Mexico, the complaint said.

The 311-page complaint describes intense pressure lower-level schemers felt from higher-up cartel figures. One defendant, Carlos Parra-Pedroza, was allegedly captured on wiretap recordings telling an informant that cartel brass are uneducated but ruthless, as well as sticklers for precision.

"If I tell them we always pay them on Tuesday (but that this time) it's not going to be until Wednesday, they'll kill me," Parra-Pedroza says, according to the complaint. "These guys (who) don't even know the word 'school,' only know how to shoot." He also warns enforcers cut off the fingers of those who betray the cartel.

The US Attorney's office in Chicago has had success convicting high-level Sinaloa traffickers in recent years. Agency heads have also spoken about the need to disrupt channels through which Mexican syndicates repatriate their ill-gotten gains.

In some excerpts from wiretaps cited in the new complaint, money launderers complain about increasingly tough laundering laws adopted in Mexico, saying the legislation forced cartels to be more sophisticated about washing dirty money.