Take the following scenario, which may happen in tournaments that's why I'm asking my question:

A famous old GM who's not playing well plays against some teenager who's very strong, The GM will be embarrassed to lose against some teenager, the GM has a lot of money, the teenager needs money for college. So the GM pays the teenager so he could win.

Or maybe could they manipulate results by mutual agreement, like what happened to [Algeria in the world cup 1982](http://www.theguardian.com/football/2010/jun/13/1982-world-cup-algeria). Could they agree to eliminate an opponent? What the rules has to say?

I know it's against the rules, i just want to know how they investigate it and what are the rules about it, and yes i'm also asking about draws, since manipulating the results isn't only about winning and losing.

And I'm also interested in knowing if the officials can deny a draw, if they see that the game is still playable or if they see something suspicious about it. And could you draw at any stage of the game: like `d3` `e5` and they agree to draw here, is it possible?