The fund's previous four-star rating was a reflection of S&P's high regard for Harrop, the rating agency said.
Clay Smolinski will take over the portfolio manager responsibilities for the Europe fund.
Smolinski joined Platinum in 2005 as a trainee analyst and has been part of the global analyst pool, working directly under Harrop's supervision. "The fund will be placed on hold until S&P has had an opportunity to meet with Mr Smolinski," S&P Fund Services analyst Leanne Fook said.