The Swiss bank took its objection over a regulatory investigation of a sordid spy saga to Switzerland's highest court – and lost.

Switzerland's federal court dismissed Credit Suisse's attempt to get a Quinn Emanuel investigator dislodged from a Swiss regulatory probe into surveillance of a former top executive at the bank, Swiss newswire «AWP» (in German) reported on Wednesday. This is the second defeat Credit Suisse has suffered in trying to shake Thomas Werlen, the U.S. law firm's managing partner in Switzerland.

The ruling represents a resounding defeat for Chairman Urs Rohner less than three months before he leaves in the wake of an ugly corporate espionage scandal. Credit Suisse was caught spying on Iqbal Khan and at least one other top executive. 

Investigator's Impartiality 

The scandal led Credit Suisse to sack its operating chief for cause and later to dismiss CEO Tidjane Thiam. Lloyd's boss António Horta-Osório is due to replace Rohner in three months as well.

Credit Suisse had argued Werlen, appointed by Finma as an outside auditor of the spying, isn't impartial because he represented creditors in a 5.4 million Swiss franc ($6 million) claim in a previous case against the Swiss bank. The Swiss court didn't accept this, ruling that there is no connection between the two cases.

Invasive Electronic Sweep

Werlen actually handed in his report to Finma in August, but the investigation halted while Credit Suisse fought the lawyer's appointment in court. A star in legal circles, Werlen reportedly attempted to seize mobile phone data from all Credit Suisse top executives as well as board members.

This made Quinn Emanuel's investigation far more invasive than Credit Suisse's own hasty probe through law firm Homburger, which found no evidence of wide-spread wrong-doing or that management knew of the spying. The bank faces enforcement proceedings by Finma, the Bern-based regulator said in September.