A US judge has in part denied Mizuho Bank’s motion to dismiss the charges filed against it in a class-action lawsuit related to its relationship with the now defunct bitcoin exchange MtGox.

Mizuho contended that it was not in a commercial relationship with plaintiffs because they were Mt. Gox’s, not its, customers. However, according to a court order dated 26th August, US District Judge Gary Feinerman said that as Mizuho accepted the money wired by the plaintiffs, the parties were in a “transactional relationship”. Feinerman ruled that the bank must face charges related to “unjust enrichment and fraudulent concealment”.

To fund their activities on the exchange, Mt. Gox users could either transfer bitcoins directly into their accounts at the exchange or wire fiat currency to Mizuho, which would deposit the money into a bank account it held on behalf of Mt. Gox. Mizuho earned service fees from processing those wire deposits.

“Mizuho stopped processing withdrawals but continued accepting wire transfer deposits (and reaping the associated fees) from Mt. Gox users. It did so in an environment in which press reports discussed delays of, but not absolute bars to, withdrawals of fiat currency from Mt. Gox’s accounts”, the judge noted.

The bank, however, succeeded in getting a charge for tortious interference dismissed. Feinerman noted that Mizuho "intends to raise foreign law at a later stage in the litigation", which means that it may try to invoke Japanese regulation, CoinDesk reported.

“Mizuho’s motion to dismiss is granted in part and denied in  part. The motion is granted as to Greene’s tortious interference with contract claim against Mizuho and as to Plaintiffs’ accounting claim against Mizuho, and otherwise is denied. Mizuho shall answer the surviving portions of the operative complaint by September 16, 2016”, Feinerman said.