They do place bets at Pinnacle and SBO. These might not be the top dogs, or biggest bets - but bets are made. An example would be for Canadian soccer where only Pinnacle from the main books continued to offer odds. Massive line changes pre game, which suggests abnormal betting patterns......
But I agree these wont be the biggest bets - those will be at books we have never heard of which is why I mentioned the darknet.
http://www.declanhill.com/blog/item/...anadian-soccer
Matches can be televised. Or a stream available. The Gold cup tournament, last two were fixed, all games televised and bets were again placed at the mainstream books.....
http://uk.eurosport.yahoo.com/091220...mes-fixed.html
One of the biggest fixes was Argentina 4-1 Nigeria friendly, again televised and again big bets were taken at Betfair and mainstream books.
http://www.huffingtonpost.com/2011/0..._n_871345.html
It wont always be "the whole team" on the fix. Often its a few defenders, goalkeeper or referee. In the Argentina game it was the referee, he got lifetime ban I believe. (late penalty was given). In the champions league game involving Debrecen and Liverpool - it was just the goalkeeper.....