A division of Switzerland's second-largest lender and one of its former advisors have agreed to pay a hefty fine to resolve a case with the US' biggest regulator.

Credit Suisse's securities arm and a former investment advisor will pay around $8 million to settle charges relating to improper investments, the US Securities and Exchange Commission said earlier this week.

According to the watchdog's order issued on Tuesday, the Swiss banking giant collected approximately $3.2 million in avoidable fees from clients between 2009 and 2014, around $2.5 million of which was generated from Sanford Katz's advisory clients.

As a result, Credit Suisse and Katz have agreed to pay disgorgement of around $3.2 million, $600,000 in prejudgement interest, and fines totalling around $4.1 million. Neither party admitted nor denied the SEC's findings. 

Katz, who was a managing director and relationship manager at Credit Suisse's San Francisco office, purchased or held Class A mutual fund shares for advisory clients who were eligible to hold less expensive institutional share classes of the same mutual funds, the SEC said. 

Family Wealth Report has reached out to Credit Suisse for comment on the matter and will update coverage accordingly.