The World football authorities will examine the finer details of his financial role to the FAI to help fund some the salary .Billionaire businessman O'Brien will contribute a sizeable chunk of Trapattoni's reputed €4m over the duration of his two-year contract with the FAI.
Fifa will ask the FAI for clarification on the finer details of the subsidy.
A Fifa spokesperson told the Sunday Independent
"At present there appears to be no regulation to prevent the deal,but certainly we will be seeking further official details from the national organisation and we are investigating the matter. Beyond that I can not comment."
Meanwhile the FAI are satisfied that no rules or regulations have been broken.
A FAI spokesperson told the Star
"Fifa do take a dim view of outside interests being involved but only if there is interference of they having a say.
"It was an unsolicited offer with no strings attached. O'Brien has had no say in the appointment and will have no say in any aspect of the running the association.
"The offer was made in writing for the board where it clearly states there were no strings attached."