The Canadian arm of global legal giant Dentons fell prey to a sophisticated scam that resulted in the inadvertent transfer of $2.5m in client funds to a fraudster’s Hong Kong account, according to a court ruling in Canada.

A description of the elaborate con, which affected Dentons Canada in early 2017, came in a 11 December decision by Judge Carole Brown of the Superior Court of Justice for Ontario. Brown is considering a dispute between the law firm and insurer Trisura Guarantee Insurance over whether Trisura must cover a little more than $1.73m in losses that Dentons claimed after the cyber incident. The judge ultimately found that she didn’t yet have enough information to determine the proper insurance coverage and pushed for further proceedings.