Huawei’s CFO Meng Wanzhou was arrested Saturday in Canada as part of a U.S. investigation into an alleged scheme to evade American sanctions against Iran.

Reuters has now learned that the investigation looked into potential bank fraud involving HSBC, the news service reported Friday.

Citing “people familiar with the probe,” the investigation has attempted to determine whether Huawei used HSBC for its illegal transactions with Iran — something that could lead to bank-fraud charges.

The report says:

“Companies are barred from using the U.S. financial system to funnel goods and services to sanctioned entities. If the mobile phone and telecoms equipment maker conducted such transactions and then misled HSBC about their true nature, it could be guilty of bank fraud, experts say.”

Related: Arrested Huawei Executive Reportedly Linked to Firm That Once Tried to Sell U.S. Goods to Iran