The extradition hearing of Meng Wanzhou, Huawei’s CFO, continues this week, and the focus was on serial numbers linked to Meng’s electronic devices.

Ben Chang, a former Royal Canadian Mounted Police officer is accused of sharing the information with the U.S. investigators for the devices of Meng.

A lawyer for Canada’s attorney general says there’s no evidence police shared that information with U.S. investigators.

The Canadian judge overseeing Meng’s extradition case questioned a federal prosecutor on Thursday about why the key witness, a retired police officer, had declined to testify.

The defense lawyer Scott Fenton said that Chang’s refusal to submit to cross-examination is “one of the more troubling elements in the case”.

The defense said that the warrant that resulted in Meng’s arrest had been obtained by U.S. misrepresentations; that Canadian police ignored the warrant’s request to arrest Meng “immediately”, to facilitate a covert probe; authorities acted as agents of the FBI; border officers unlawfully shared information with the FBI and Canada’s spy agency; and the police unlawfully searched Meng’s electronic devices and provided more information to the FBI.

The prosecution was expected to resume arguments and the hearings on Meng’s extradition are scheduled to conclude in May.

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