Intel has always maintained that its business practices around the world are legitimate and above board. The FCO didn't say who filed the complaint, only that it was made by an Intel competitor. Nor would the organisation reveal what the complaint alleges. However, it's hard not to assume that the grumble relates to the Metro claims.
While all fingers may point to AMD, and they haven't explicitly denied it yet, there are other potentials out there. Regardless, this may have a big impact on the other investigations currently ongoing in other countries.