Late on Tuesday, the Swiss Federal Administrative Court called the Swiss Financial Market Supervisory Authority's (FINMA) calculation of the amount seized from Banca della Svizzera Italiana (BSI) "incomprehensible" and ordered FINMA to reassess.

EFG bought BSI three years ago from Brazil's BTG Pactual after the Lugano-based private bank became entangled in legal problems related to the scandal-hit Malaysian sovereign fund 1MDB, which resulted in the closure of BSI's Singapore branch in 2016.

In the case, FINMA concluded BSI breached money laundering rules and ordered it to hand over profits amounting to 95 million Swiss francs (74 million pounds), prompting a BSI appeal on grounds the supervisor's procedure was flawed. In its decision, the Swiss Federal Administrative Court concluded FINMA must take up the matter again.

"Although acknowledging the occurrence of severe violations of supervisory provisions the Swiss Federal Administrative Court (FAC) considers the estimate of 95 million francs to be incomprehensible," the court wrote. "The confiscation has to correspond to the actual profit generated by the infringement."

Even if FINMA concluded it confiscated too much money from BSI, EFG International said that would not mean a results-boosting windfall for the Swiss company.

"The final purchase price of EFG's acquisition of BSI accounted for a respective provision," EFG said in a statement. "Any modification in the amount of disgorgement would be neutral to EFG's financial results."

By John Miller