Hypothetical Tax: Its impact on the employer and employee

Hello Sir and thank you again for this article. We are facing here in Equatorial Guinea this tax "Hypo Tax". But to our great surprise it is registered as a business expense and is considered a deductible charge by most oil contractors. Being a member of the tax administration, I wonder if this is a withholding tax applied on the salary of the employee by the parent company or a charge of the company hosting the expatriate staff? Because during our tax audits we find exorbitant amounts of this tax in the accounts of companies audited. Are they tax deductible?