I think that the best way to deal with an unresponsive team member is to schedule a meeting with them either in person or over the phone. In the meeting I would discuss their unresponsiveness with them and hear from them why they have been so unresponsive to clear up any potential misunderstandings. I would also encourage them to be more responsive and participate more, and mention the consequences of their continued poor responsiveness. Hopefully this meeting would serve as a wakeup call for this team member and they begin to improve their communication, otherwise I would consider releasing them from the project team.