Ask HN: Hackathon money stolen by a teammate. What to do?

Few months ago I went to a hackathon and met few other developers and non-developers. We formed a team, build the app and won $5000 in cash prize. The organizers asked us to designate one of the team members as a recipient of the money so he/she can distribute it to the rest of the team members. One of the team member was overly enthusiastic of distributing the money, so we designated him. After couple of months the organizers transferred the money to the designated person. This guy since then has "disappeared" with the money. No response to our emails, text or phone calls. Its been 2 months since the money was transferred to him.

What to do in this situation ?