It's possible:
* He's not publicly known for acting or directing: His work might be in other areas of film or television production, or he might not be publicly listed as a participant in projects.
* The name is misspelled: Perhaps you have a slightly different spelling of the name in mind.
* The person is new to the industry: He may be a newer talent who hasn't had any major projects yet.
To find more information, you might need to:
* Provide more details: Do you have any other information about the person, such as where they are from or what kind of projects they work on?
* Check online film databases: Websites like IMDb and FilmAffinity can be useful for searching for individuals in the film industry.
* Use a search engine: Search for "Stephen Tsang film" or "Stephen Tsang television" to see what results come up.
Please provide more context so I can help you find more information!