TikTok has been accused of mishandling allegations of sexual misconduct and harassment against a senior manager in London, highlighting longstanding concerns about the working culture at the fast-growing social media platform.

Steve Ware, former head of TikTok’s UK e-commerce studio operations, made inappropriate sexual comments and advances to young female staff members and clients, including influencers who create content on the app, according to four women who worked with him at TikTok.

Ware has told the Financial Times that all allegations against him are “false.”