Swiss authorities are investigating possible money-laundering related to charges that Statoil ASA, Norway’s largest oil company, paid bribes to win business in Iran, the Swiss Federal Prosecutor’s Office said.

Swiss authorities involved in the global hunt for terror money have established that both Osama bin Laden and suspected al-Qaida No 2 Ayman al-Zawahiri had links to Swiss bank accounts.

The Swiss ambassador to Luxembourg has been arrested on suspicion of money laundering.