BEIJING, July 5 (TMTPOST) — Hong Kong-based beverage maker Vitasoy's share price plunged by 11.22% to HK$26.1 on Monday on the back of a controversy, the lowest since last September, reducing the company's valuation to HK$27.9 billion. Several Chinese celebrities had terminated their cooperation with the brand. It is reported that a number of retailers in mainland China are removing Vitasoy's products from their shelves. The controversy was sparked by Vitasoy's internal memo that commented on a recent attack on local police involving one member of its staff. The Vitasoy employee attacked and stabbed a local policeman with a knife and committed suicide. It is reported that the Vitasoy employee was a subscriber to the local separatist movement. The internal memo, which seemingly shows support for the attacker, has drawn heavy criticism in mainland China.