Manchester City face being hit by a transfer ban from FIFA in the coming days.
The Blues were also fined almost £400,000 for a similar offence and it is claimed an announcement is "coming very soon".
Should City been handed a ban, they will be unable to strengthen their squad at the end of the season.
City could also face further fines after another FIFA probe into an apparent breach of FFP guidelines.
German magazine Der Spiegel claims that some of their lucrative sponsorship deals are being financed by owner Sheikh Mansour.