Cambridge Analytica suspended its chief executive, Alexander Nix, and said it is launching an independent investigation to determine if the company engaged in any wrongdoing in its work on political campaigns.

The moves followed the release of a video on Monday that depicted Mr. Nix touting campaign tactics such as entrapping political opponents with bribes and sex. The sales pitch was captured by undercover journalists at British broadcaster Channel 4. Mr. Nix’s suspension also follows reports that the company improperly...