The Charity Commission is examining a complaint that Esther Rantzen has broken political campaigning rules by using her personal assistant, whose salary is part-funded by the NSPCC, to work on her parliamentary campaign.
Rantzen, who is president of ChildLine and a trustee of the NSPCC, is standing as independent candidate in Luton South.
She employs a part-time personal assistant, half of whose salary is reimbursed to her by the charity because the assistant spends half of her time facilitating Rantzen's work for ChildLine and the NSPCC.
A Charity Commission spokeswoman confirmed it had received a complaint about the personal assistant and said it was assessing whether to investigate the case.
Rantzen told Third Sector she had not broken any rules. She said the charity had not reimbursed her for the personal assistant's salary since March 2009, but she had only recently realised this and did not know how it had happened.
"After the general election, I will talk to the NSPCC about this," she said.
She said she would not consider allowing ChildLine or the NSPCC to become involved in her campaign to be elected.