The Taoiseach, Mr Ahern, may have to change his personal statement to the Public Offices Commission because of a "benefit in kind" involving the use of a constituency office.
The commission is dealing with political contributions received during 1997.
Last week it replied to the Taoiseach about questions he had raised as to his precise legal obligations under the Electoral Amendment Act.
The commission is understood to be awaiting a response.
In his statement of donations for political purposes, the Taoiseach declared a total of £3,000 received in two financial contributions during the 1997 general election.
But he provided no information about the costly operation run on his behalf in the Dublin Central constituency from a house called St Luke's in Drumcondra.
The St Luke's building, which is owned by five named trustees on behalf of Fianna Fail, cost in the region of £100,000 in 1988. It is used by the Taoiseach for constituency clinics and also for official and party business during working days.
The provisions of the Electoral Act require every TD to account for all contributions in excess of £500, including any benefit in kind or the donation of property or goods.
When some details of this possible oversight were published by the Sunday Tribune last June, a spokesman for Mr Ahern said that he was not required to make any declaration about St Luke's as it was being used by the Fianna Fail party.
But he undertook to raise the matter with the commission.
It would be extremely embarrassing, to put it mildly, if the Taoiseach was now required to amend his formal statement in relation to political contributions, especially as Fianna Fail confirmed that it provided the commission with inaccurate information in relation to a "pick-me-up" payment.
The commission yesterday laid a report on the latter issue before the Dail, and said it was "considering the matter pursuant to the relevant provisions of the legislation."
On July 6th the commission wrote to Mr Des Richardson, Fianna Fail's fundraiser, inquiring whether any "pick-me-up" payments in excess of £4,000 had been received by the party after May 15th, 1997.
An initial response was in the negative.
But on July 30th, Mr Richardson wrote to say that a very indepth trawl of the party's records showed that an invoice which the party had been advised was paid prior to May 15th (when the legislation took effect) was not in fact paid until May 30th.
The amount involved was £10,000, plus VAT at 12.5 per cent, and was paid by Frank Dunlop and Associates of Upper Mount Street, Dublin 2.
There are now three courses of action open to the commission. It may accept the Fianna Fail explanation at face value; it may remind the party of its obligations under the Act (which would be the equivalent of a reprimand), or it may refer the matter to the Director of Public Prosecutions.
Already the commission has referred to the Garda 20 cases of failures by unsuccessful Dail candidates to make returns, and six of those are before the courts at present.