Huawei executive Meng Wanzhou's lawyers went to court on Monday to press for the release of classified documents related to her arrest that they claim will show her rights were violated.
Meng, the Chinese telecom giant's chief financial officer, was arrested on a US warrant in December 2018 during a stopover in Vancouver.
She is charged with bank fraud related to violations of US sanctions against Iran, and has been fighting extradition ever since.
Appearing by teleconference at the British Columbia Supreme Court, defense lawyers said the Crown must not be allowed to shield authorities' misconduct by blocking the release of key documents.
They pointed to "inconsistencies" in the reasons given by the attorney general for redacting or withholding them.
Defense lawyer Mona Duckett said the documents in question contain "important information that ought to have been provided at the get-go."
Instead, she said, the Crown has continually changed its justifications for keeping them secret.
Canadian government lawyer John Gibb-Carsley retorted that all relevant documents were given to the defense.
"The Attorney General of Canada cast the net very wide to capture all documents," said Gibb-Carsley.
- Abuse of process alleged -
Meng's defense team alleges that the Federal Bureau of Investigation (FBI) conspired with Canadian authorities to collect evidence and interrogate her, in violation of her rights.
Specifically, they point to her detention and questioning without a lawyer over the three hours after she disembarked a flight from Hong Kong, but before she was charged, as well as the illegal seizure of her electronic devices.
The Royal Canadian Mounted Police (RCMP), the defense says, noted the serial numbers and technical specifications of her smartphones, tablet and laptop computer and improperly gave these details to the FBI.
Most of the almost 400 documents sought concern communications between Canadian and US agencies prior to and after Meng's arrest.
The court previously ordered the Canadian Security Intelligence Service (CSIS) to hand over a stash of files to the defense, but they were mostly blacked out. The defense wants those redactions lifted.
Meng's legal team is expected to argue that the extradition proceedings should be stayed as a result of the alleged abuse of process.
The RCMP has denied any wrongdoing, while the Crown on Monday continued to argue against the release of more documents on the basis of relevance, legal privilege and national security.
This week's hearing is scheduled to take up to five days, with the remainder of the sessions to be held behind closed doors.
Meng remains under house arrest in Vancouver while the extradition case, which is due to wrap up in April 2021, is heard.
Meanwhile, the US government on Monday expanded its sanctions on Huawei, a move aimed at further limiting the tech giant's access to computer chips and other technology.
US officials have argued Huawei poses a security risk because of its links to the Beijing government, a claim denied by the company.