Amina Zakari, a commissioner with the Independent National Electoral Commission (INEC) has said she is not a niece or cousin to President Muhammadu Buhari.
There had been speculations that she is a "blood relation" of the president, with calls for her removal as head of the collection centre committee.
The presidency, however, denied the claims in a statement issued by Garba Shehu, the president's spokesman, on Friday.
Zakari also denied the claim in an interview aired by BBC on Friday.
Her words: "I'm not his niece. I'm not his cousin. And on this job, I've been appointed since 2010 by President Jonathan and prior to that, I was appointed an SA to President Obasanjo and I've done my work conscientiously over the years as a patriotic citizen of Nigeria, and I don't think I should be distracted now that elections are coming forward.
"I'll continue doing my work. I'll continue serving my country to the best of my ability with the best of intentions.
"President Muhammadu Buhari is my president as everybody else's president. He's not my cousin; he's not my uncle as is being claimed. That's all I can say. But I know him as my leader, as a leader of the nation."