UEFA supremo Aleksander Ceferin says they're prepared to punish Manchester City if they're found guilty of breaking financial football laws.
Reports last week suggested City may face a Champions League ban if found guilty with UEFA referring the case to Club Financial Control Body adjudicatory chamber.
“Sometimes we forget how dirty this industry is," Ceferin told the New York Times.
City were fined and hit with a restriction on transfer spending after an initial breach in 2014 while PSG's dealings have also been investigated.
There have been fears European heavyweights such as City and PSG would manage to avoid a heavy sanction, while lesser names wouldn't be as fortunate.
But Ceferin added: "If you do it right, you don't sell yourself.
"If you are not involved in any strange business, if you are not corrupted, then you go straight forward and be fair to anyone."