The arrests followed house searches at six locations on Monday in collaboration with police from three cantons, the Zurich prosecutor and Italian authorities, Swissmedic said in a press release.
The agency noted that medical products made from human or animal tissue, and containing no living cells, are subject to Switzerland's Therapeutic Products Act and require the approval of Swissmedic.
The manufacture and distribution of such preparations, as well as their import, wholesale trading or export must be approved by the agency, it added.
The searches on Monday were carried out as part of an ongoing investigation involving police from the cantons of Zurich, Thurgau and Aargau, the public prosecutor of Limmatal/Albis and Italian authorities.
No information was disclosed about the three people, who have been provisionally detained while the investigation continues.
The accused individuals are presumed to be innocent until proven guilty, Swissmedic said.
The agency said medical products using non-living cells of humans or animals should not be confused with “fresh cell” therapies.
The use of live animal cells is known as “xenotransplantation” and is subject in Switzerland to the Transplantation Act, Swissmedic said.