Credit Suisse is to investigate claims that it had Iqbal Khan tailed by a surveillance team ahead of his move to rival UBS.
The departing CEO of international wealth management filed a report with Zurich police after a confrontation with three unidentified men, who were trailing him by car and on foot when he was with his wife and child.
Khan attempted to photograph the car used by the three men, at which point one of the men tried to take his phone.
The three men fled when the altercation drew the attention of passers-by, but were eventually detained for questioning.
Credit Suisse has decided to launch an investigation into the matter, with those in charge reporting directly to the chairman of the board of directors.
The Swiss bank adds that it will not be commenting further until the investigation is completed.
Reports circulated in Swiss and German media that Khan, currently on a three-month term of garden leave, was under surveillance by his employer over suspicions that he was trying to poach a colleague for UBS.
A Credit Suisse employee, acting as a spokesman for Khan, described this suggestion as “totally absurd”.
Iqbal Khan had been tipped as a potential successor to Credit Suisse CEO Tidjane Thiam.
He is set to commence his new position at UBS on October 1, replacing Martin Blessing who had held the post since last February.