gold as collateral, page-6

I think you're right Colinchi, I also think that is what the report is saying. The mechanism itself is in the open i.e the banks that sit on the panel.

A potential conflict of interest comes in to play when banks that set the price according to 'rules' may also be involved in trading prior, before and after the 10am and 3.30pm fixings.

I suppose that is what the regulatory bodies are looking closely at - the market actions of those with the power (cash/gold) and knowledge to move the market while at the same time setting the benchmark price.