Premier League chief executive Richard Masters has told the BBC it has "ways of being comfortable and satisfied" that the Saudi state will not interfere with the running of Newcastle United.
The Premier League had received "legally binding assurances" that the Saudi state would not control the club.
Masters says the owners can be removed if "evidence to the contrary" is found.
However, he admitted that the league may not necessarily be aware if the country's Crown Prince - who is also the chairman of PIF - gave orders to the club's directors.
Speaking to BBC Sports Editor Dan Roan in his first public comments since the league approved the deal, Masters added: "In that instance, I don't think we would know.