Champions Manchester City are being investigated by the Premier League for possible breaches of Financial Fair Play (FFP) regulations.
FIFA, UEFA and The Football Association are also looking into the club's off-the-field activities, including the signings of young players.
German magazine Der Spiegel have accused the club of evading the rules for years.
A statement read: "The Premier League has previously contacted Manchester City to request information regarding recent allegations and is in ongoing dialogue with the club.
"The league has detailed financial regulations and strong rules in the areas of Academy player recruitment and third-party ownership.
"We are currently investigating these matter and will allow Manchester City every opportunity to explain the context and detail surrounding them.
"We will make no further comment until this process has concluded."
The publication claimed the regime led by Sheikh Mansour since 2009 topped up multi-million-pound sponsorship deals with Abu Dhabi companies, using their owner's fortune, allowing them to stay within the rules.
Man City have denied any wrongdoing and have welcomed the action taken by UEFA.
Further scrutiny over City's dealings come amid an ongoing investigation by FIFA into the acquisition of several young players.
Among the allegations are suggestions City paid the families of young stars and that they fielded players in organised matches without an international transfer certificate.
Chelsea have been handed a two-transfer window ban for 29 breaches of the rules over signing youngsters and have seen an appeal to freeze the ban rejected by UEFA.