According to this link:

http://www.immigration.gov.mv/index.php?option=com_content&view=article&id=110&Itemid=93

Under the Foreign Employment tab, it says

"Employment for foreigners is allowed only under the permission granted from the Foreign Employment Division of Immigration."

Where are your sources for the Business Visa being acceptable for someone to teach English? While this page does not mention English specifically, being a teacher, means one is employed, and the only way to be employed legally is through the FEDI.

I would warn to be wary of above person's comments, as working in China as an English Teacher on a business visa is illegal, show us wher eyou have seen that a business visa is acceptable.