GENEVA (AP) — Swiss prosecutors have opened a criminal investigation into whether the country's biggest bank, UBS, helped launder money linked to illegal rainforest logging in Malaysia.

Federal Prosecutors' Office spokeswoman Jeannette Balmer confirmed the probe on Friday.

The investigation follows a complaint from a Swiss environmental group. The Bruno Manser Foundation alleges that Musa Aman, the chief minister of the Malaysian state of Sabah, used UBS bank accounts in Hong Kong to launder over $90 million linked to logging operations on Borneo.

Musa Aman is the brother of the Malaysian Foreign Minister Anifah Aman.

UBS said in a statement Friday that it "applies the highest standards worldwide in the fight against money laundering and corruption" and that it would "cooperate fully" with Swiss authorities.