8. Where, owing to a special relationship between the payer and the person deriving the interest or between both of them and some other person, the amount of the interest paid exceeds for whatever reason the amount which would have been paid in the absence of such relationship, the provisions of this Article shall apply only to the last-mentioned amount. In that case, the excess part of the payments shall remain taxable according to the law of each Contracting State, due regard being had to the other provisions of this Convention.