SINÉAD O'CONNOR says Ian Bailey frightened her after the two were pictured having lunch together outside a Cork restaurant this week.
She admitted that Bailey was a "charming" man while sober, but that it was a "different story" after five hours of drinking.
"Ian Bailey is charming sober - but drunk, for a woman, he is frightening," the Nothing Compares 2 U singer told the Irish Sun.
"The man I met at lunch was a different story to the man I met five hours later with a pile of drink on him. I can certainly see how someone other than myself would have felt very threatened."
However, Manchester-born Bailey disputes these claims, stressing that he was "very calm and measured" during their meeting.
Something of a war of words has broken out between the two since their interview - on behalf of the Irish Sunday Independent.
Bailey claimed that the Irish singer wanted to turn some of his poetry into songs, something O'Connor later dismissed as "lies".
Yesterday I asked Ian Bailey 5 questions other reporters have never asked but should. During the course of our interview which was filmed and transcribed for The Irish Sunday Independent, Bailey made his very 1st ever public plea for the real killer/killers to come forward.
— Sinead O'Connor (Shuhada Sadaqat) (@MagdaDavitt77) July 15, 2021
Irish singing sensation, Sinead O’Connor, in conversation with Ian Bailey in Glengarriff. pic.twitter.com/v4xAiBo9tV
— The Southern Star (@SouthernStarIRL) July 15, 2021
"Bailey lying his face off in the Star today. Saying we were discussing putting his poems to music. NEVER happened," Ms O'Connor tweeted on Thursday.
"Can star call me to confirm in future before they run his lies?"
Bailey is the self-confessed prime suspect in the murder of Sophie Toscan du Plantier - a French filmmaker who was killed outside her home near Schull, Co. Cork in 1996.
The investigation, which remains unsolved to this day, has been thrust back into the spotlight this month following the release of two documentary series about the case, on Sky and on Netflix.
O'Connor claims that during their lunch, she asked Bailey five questions "that no one has asked him before".
"They worked because when I asked them, Bailey got panicky very quickly. In fact, he freaked out, lost his s***," she said.