A candidate for the Ulster Unionist Party leadership has been reported to the party's disciplinary committee.
It is understood the complaint is that Fermanagh politician Tom Elliott announced his candidacy too early.
He said he would stand for the post in June, but party leader Sir Reg Empey only officially announced his resignation last week.
Mr Elliott said the complaint was "incredibly petty" and that there was no rule stopping him announcing his intention to run for the leadership.
Sir Reg said he would resign earlier this year following disappointing results in the general election.
A selection meeting for the new party leader is due to be held at the Waterfront Hall in Belfast in September.
The new leader is expected to be in place ahead of its party conference in late October or early November.