The Justice Department Wednesday said that an Orinda couple were part of a group that conspired to steal production secrets worth billions of dollars from U.S. chemical giant DuPont and detailed a plot investigators allege was aimed at relaying those secrets back to China for use in that country's own factories.

Walter Liew, 54, and his wife Christina, 49, were both charged Wednesday with conspiracy to commit economic espionage, attempted theft of trade secrets, possession of trade secrets and conspiracy, false statements and witness tampering.

The evolving, multi-billion dollar plot was revealed as five people and five companies were indicted Wednesday for allegedly stealing trade secrets to directly benefiting companies under the control of the People’s Republic of China.

The cabal of alleged spies was reportedly focused on obtaining a valuable pigment known as titanium dioxide, a substance that gives a white, reflective glow in coloring paint, plastics, paper and other commercial products. Wednesday's Justice Department indictment charges that the Chinese tried to steal production technology from DuPont and use it to open a titanium dioxide plant at Chongqing, China.

Federal investigators allege that "companies controlled by the PRC government, specifically the Pangang Group companies… conspired and attempted to illegally obtain titanium dioxide technology..."

Pangang and four other corporate defendants are charged with conspiracy to commit economic espionage, conspiracy to commit theft of trade secrets and attempted economic espionage. The Justice Department said the Pangang Group companies paid significant sums of money to at least five people, including the Liews, in exchange for DuPont’s trade secrets. 

Walter Liew, also known as Liu Yuanxuan, is a naturalized U.S. citizen and co-owner of the Oakland-based USA Performance Technology, Inc.

Liew was charged in August 2011 with obstruction of justice and making false statements to the FBI. He was arrested at that time and has been ordered detained pending trial because he is believed to be a flight risk.

Christina Liew, also a naturalized U.S. citizen and co-owner of USAPTI, is similarly charged and currently free, though she has been admonished not to leave the country and her whereabouts are monitored electronically.