CNN Business (CNN Business) The chief financial officer of Chinese tech giant Huawei was back in a Canadian court Wednesday for what is shaping up to be a very long battle against extradition to the United States.

The case has been a flashpoint for already strained US-China relations . And there's no end in sight.

Meng Wanzhou, the Huawei CFO, was detained by Canadian authorities five months ago and faces extradition to the United States. Meng and Huawei face a number of charges, including bank fraud, trade secrets theft and sanctions evasion, in US federal courts.

Huawei has repeatedly denied wrongdoing. The company said "political factors" are at play and in Meng faces a "serious violation of justice." It said she plans to ask the Canadian court to stop the extradition case from going forward.

"Political factors at play during the extradition process may lead to a serious violation of justice," the company said Wednesday. "Ms. Meng's legitimate rights may also be harmed." Meng earlier filed a civil lawsuit accusing Canada of illegally detaining her.

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