Several Chinese traders are complaining that they were duped into providing loans against artificially inflated aluminum stockpiles, less than a decade after the market was roiled by a similar scandal on a much bigger scale.

At least three companies lent a total of more than 500-million yuan ($75-million) against stockpiles of the metal stored in a warehouse in the southern province of Guangdong that turned out to be worth significantly less than that, according to people with knowledge of the matter. They asked not to be identified because they’re not authorized to speak to the media.

Aluminum traded on the Shanghai Futures Exchange fell as speculation over the loans eroded market confidence. The metal at the center of the transactions is not held with warrants registered with the exchange, said the people.

The actions of the borrowers -- including at least one small Shanghai-based trader -- have been reported to the local police, the people said. Calls to the Guangdong provincial public security bureau went unanswered.

While the amounts so far being talked about are relatively small, traders pointed to similarities with a scandal in 2014, when one merchant fought over ownership of metal pledged many times over at warehouses in Qingdao. That incident ran into billions of dollars, sparked a crisis in the industry, and eventually changed the horizons of the commodities financing industry in China.

Commodities traders have faced a tougher environment in recent months as banks turn cautious in the wake of some high profile losses, particularly in the nickel market, and volatility caused by the Russian invasion of Ukraine. That’s encouraged some to seek alternative financing, including a practice for smaller, privately owned firms pledging their goods to larger, state-run traders to obtain cash to operate in China.

In the case this week, some creditors tried to confirm their aluminum held at a warehouse in Foshan city in Guangdong, only to discover a mismatch between receipts and the actual quantity of metal, the people said.