LISA Desmond has received anonymous and abusive letters about her rumoured relationship with Mayor Gerard O'Connell.
In a statement to the Chronicle the council CEO refuted the rumour.
"I totally reject the lies about any improper relationship with the mayor.
"I have received anonymous letters containing absolute vile about this lie.
"I have also had to defend myself to members of the community about this completely fabricated lie.
"These types of unfounded and vicious lies are sadly not unfamiliar territory for a female in a senior leadership role.
"This is a baseless and deliberately malicious lie, designed to personally damage reputations and integrity.
"It is disappointing that any female should have to endure demeaning, belittling and sexist comments, let alone accusations based on lies.
"While this aspect of my position is challenging and personally confronting, it has an even greater impact on my husband and children."