The FA have opened an investigation into Arsenal's signing of former Southampton defender Calum Chambers.
Both clubs are aware of the probe, but in the dark over the reasons for it.
The Daily Mail says suggestions of agents unrest would not normally be enough to warrant this type of FA attention.
Chambers is on the books of Cassius Sports Management, whose agent Alan Middleton, a licensed lawyer, refused to return frequent calls because a legal colleague said it was company policy not to talk to the press.
