"SIX Exchange Regulation is opening an investigation against Credit Suisse Funds AG on the grounds of possible breaches of regular reporting obligations," it said in a statement.
The regulator said that the probe centred on regulatory information which had possibly been provided late in January 2014 related to certain exchange-traded funds of Credit Suisse Funds AG.
"Within the framework of regular reporting obligations issuers are obliged to report to SIX Exchange Regulation technical and administrative information in order to guarantee smooth trading," it said.
It underlined that the potential duration of the probe had not been determined, and that no further information would be provided while the investigation was under way.
Contacted by AFP, Credit Suisse declined to comment on the probe.
News of the investigation follows reports that Switzerland's second largest bank faces a fine of at least $1 billion for its alleged role in helping US clients hide billions of dollars in assets from American clients.