In a judgment published online Friday, Justice Ronald Skolrood ordered Kuang Wan Fang to pay $670 million and her mother in-law Tan Wen Jing more than $2.5 million.
The bank launched the civil case against Kuang, her husband, Xu Chao Fan, and others in 2001 after becoming aware that it had been defrauded of US$480 million during the previous decade.
Tan was added as a defendant in March 2002.
Xu, Kuang and others were subsequently tried and convicted in a Nevada court in August 2008 of money laundering, conspiracy and fraud charges.
Xu remains in custody, but after Kuang was released, the bank pursued the civil case against her and Tan in B.C.
Skolrood said evidence, which included transcripts from trials in Hong Kong and the United States, as well as oral testimony, did not establish that Kuang participated directly in the fraud.
"However, there can be no question that she knowingly assisted in the efforts of the principal fraudsters, including her husband, to cover up the fraud and to disperse and launder the money fraudulently taken from the bank," he said.
Tan assisted in the breach of trust, he added, and failed to examine the source of large sums of money that were passing through her bank accounts.
"The facts leave little room for any conclusion other than that she was at best reckless or wilfully blind to the fraudulent origins of the funds," said Skolrood.
Ross Clark, one of the lawyers who represented the bank, said the judgment was founded on a common law principle of "knowing assistance."
"Even though the wife did not commit the fraud, and did not set up the money laundering, she participated in it and aided Mr. Xu in his successful enterprise to defraud the bank," he said.
Clark said he can't comment on how much money the bank hopes to get back, but noted it will try to collect.
Skolrood's ruling said the bank was defrauded of the money by three management employees between 1992 and 2001.
During the trial in November and December 2014, Skolrood heard evidence from an auditor who was hired as an investigator.
Liao Hai testified the bank became aware of the fraud in 2001 when it implemented a computer network that monitored foreign currency transactions at all of its branches.
He said each branch previously submitted reports to its head office, which had limited ability to test their veracity.
Skolrood also admitted as evidence a judgment from a Nevada court. It said the three bank managers engaged in foreign-exchange speculation, loans that were not properly recorded in the bank's accounting system, and false loans that were recorded but diverted to a conduit company in Hong Kong.