If you're asking the police to get involved in a private matter over people that willingly entered a tournament...where does it stop?  What law was broken?  They put weights in fish.  If you enter a 50/50 do you know who is drawing the ticket?  There could be swindling going on.  You willingly gave your $.  Nothing was stolen.
  Its little things like this that gives the state and government implied power.  It is a private tourney, deal with it accordingly.  The last thing we need in this country is more laws, regulations, and government involvement.  Its like crying to your parents as a child when your sibling steals a toy.  The police would only get involved if it became violent.  Man up and deal with it.  No need for anything further.