A trader who conspired to manipulate futures contracts in precious metals committed those actions while working at Deutsche Bank AG, according to a person familiar with the matter, and he is now cooperating with prosecutors.

The trader, David Liew, pleaded guilty to fraud on Thursday in federal court in Chicago for his role in the spoofing of contracts for gold, silver, platinum and palladium, according to court papers. Along with spoofing which is placing orders without the intent of executing them in an attempt to manipulate the price he also acknowledged front-running customers’ orders.

Liew’s cooperation suggests more headaches for Deutsche Bank and its traders. Liew worked on his own but also with at least three other traders at the bank to coordinate spoofing hundreds of times, practices he said he learned from his co-workers, according to court documents. Liew’s employer is described as Bank A in the plea agreement and identified as Deutsche Bank by the person familiar with the matter.