Huawei chief financial officer Meng Wanzhou, who is out on bail and remains under partial house arrest after she was detained last year at the behest of American authorities, carries an umbrella to shield herself from rain as she leaves her home to attend a court hearing, in Vancouver, on Thursday October 3, 2019. THE CANADIAN PRESS/Darryl Dyck

VANCOUVER - A lawyer for Huawei Technologies executive Meng Wanzhou says the RCMP illegally passed on serial numbers and other crucial identifying details of her cellphones, laptop and tablet to the Federal Bureau of Investigation.

Scott Fenton said Mounties provided information that enables U.S. authorities to find out calls made and received, phone numbers, time and duration of calls and the physical location of cell towers where calls were connected.

“This is a very serious matter,” Fenton told a British Columbia Supreme Court judge on Thursday.

“The provision of this technical information is a gateway to U.S. law enforcement taking other investigative steps ... to get other information to use against Ms. Meng.”

Meng's lawyers are in court seeking documents that they believe would prove allegations that American and Canadian officials conspired to conduct a “covert criminal investigation” at Vancouver's airport.

The U.S. is seeking her extradition on fraud charges linked to alleged violations of sanctions against Iran, which she and Huawei deny. She was arrested during a stopover at the Vancouver International Airport on Dec. 1, 2018.

Lawyers for the Canadian government argued this week that there is no indication of improper evidence sharing between the FBI, RCMP and Canada Border Services Agency.

Fenton disputed the assertion, telling the court that while the devices were ultimately not passed on to the FBI, the original plan was for the U.S. agency to acquire them.

Following a morning meeting on Dec. 1 with RCMP and CBSA officers, a Mountie wrote in her notes that the border guards would obtain Meng's phones “as per FBI request,” he told the court.

The Crown has said a forensic examination showed that neither the CBSA nor the RCMP searched the devices. However, Fenton said the exam did show that on Dec. 4, several devices were turned on and at least one was connected to internet.

That was the same day that a RCMP officer wrote in his notes that he photographed the devices and removed the SIM cards, Fenton said.

Also on Dec. 4, he said an officer emailed the FBI the devices' serial numbers, SIM card numbers and what are known as international mobile equipment identity numbers. The identity numbers allow U.S. authorities to learn significant information about call history, the defence said.

The RCMP violated the Extradition Act and Meng's constitutional rights when it passed on these details, Fenton argued.

The FBI has since dropped its request for the devices, but Fenton described that decision as “an effort at damage control” and added the agency may have already gleaned significant information from the items.

“A reasonable inference may be made that they don't want the devices anymore because they don't need them,” he said.

Fenton also criticized the Crown for its recent admission that border guards “mistakenly” provided Meng's passcodes to the RCMP.

The defence argues that a plan was hatched during a morning meeting on Dec. 1 to have border guards interrogate Meng before the RCMP executed the provisional arrest warrant, robbing her of her right to a lawyer or silence.

The court heard CBSA seized her devices and wrote down the passcodes on a piece of paper, both of which they passed to the RCMP at the time of her arrest.

Fenton questioned why handing over the passcodes was being described as a mistake, but not provided the devices. He argued that none of what unfolded was an accident.

“To describe this as an error is to mischaracterize the seriousness of all of the conduct. In our respectful submission, all of the conduct was purposeful and taken in furtherance of the plan that was set that morning.”

This report by The Canadian Press was first published Oct. 3, 2019.