Credit Suisse reportedly spied on its former main private banker, Iqbal Khan, outside of Switzerland. The Swiss bank was also having the top executive tailed far earlier than last autumn.

A September confrontation between Iqbal Khan and a private detective in a tony Zurich street abutting Credit Suisse's headquarters on Paradeplatz apparently wasn't the first time the Swiss bank had its top executive tailed, Swiss business outlet «Handelszeitung» (in German) reported on Thursday.

Last March, detectives followed Khan in Hong Kong during the wealth manager's annual Asian conference, the newspaper reported, citing several undisclosed sources familiar with the events. The paper didn't specifically disclose whether Credit Suisse had ordered the surveillance.

Lost in Masses

The detectives, who were recruited locally, ended the covert operation after losing track of Khan, it said. The incident took place around the time that Khan's name began circulating in Zurich banking circles as a natural successor to Credit Suisse CEO Tidjane Thiam – and as elsewhere, as finews.com reported at the time.

It isn't clear whether the latest spy incident can be tracked back Pierre-Olivier Bouée, a long-time Thiam associate who most recently was operating chief at Credit Suisse. The Frenchman took the blame for spying on Khan and on another banker. He is weighing legal steps, finews.com reported two weeks ago.