A Chinese tennis star who appeared to make allegations of sexual abuse against a former top official in the all-powerful Communist Party has seen her online presence blocked and her name wiped from social media. The reported claims by Wimbledon doubles champion Peng Shuai, 35, against former vice-premier Zhang Gaoli, 75, mark the country’s highest-profile allegations of their kind and come just days before a major meeting of the Communist leadership. Activists said the claims revealed the “excessive abuses of power” of China’s ruling elite. In a social media post that was almost instantly removed, Peng described a more than…