Appearing on ITV’s Good Morning Britain, the 34-year-old US businesswoman refused several times to deny that she had previously had an affair with Mr Johnson and said he had “never given her any favouritism”.
Ms Arcuri admitted that the Prime Minister had been to her Shoreditch office and home “five, ten, a handful of times” and described him as “a really good friend”.
But she added: “It’s really not anyone’s business what private life we had.”
Ms Arcuri also said the Prime Minister “asked me to show him a few things” on a pole she had for dancing in her London home.
Describing the kit as a “conversation starter,” she said she and Mr Johnson “always had a laugh about it”.
“The pole stood in the living room, yes, he saw the pole,” she said.
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When asked directly whether Mr Johnson had ever used the pole, Ms Arcuri said: “I’m never going to tell you that.”
The technology entrepreneur and former model was reportedly given £126,000 in public money and privileged access to three foreign trade missions led by Mr Johnson while he was in City Hall.
The government has since frozen a £100,000 grant to Ms Arcuri’s company, Hacker House, pending a review.
Mr Johnson has been given 24 hours to provide details of their relationship to a conflict-of-interests probe in the London Assembly – whose rules forbid favourable treatment to friends.
But asked on Monday if he would agree to appear before the London Assembly’s elected members, Mr Johnson replied: “I've said everything I'm going to say on that particular subject.”
If he fails to respond to the request he could be summoned by the Assembly. If he then refused to attend Mr Johnson would face an unlimted fine or jail term of up to three months.
Last week, Ms Arcuri told the Daily Mirror that allegations of an affair with Mr Johnson were “bull****”.
“If I was banging the dude and there was some kind of, like trail or sex tape, but there's nothing,” she told the newspaper.
“There is a human side of my very complex relationship. This is not a Monica Lewinsky.”
The Prime Minister is currently engaged in frantic negotiations with European politicians after being told by French President Emmanuel Macron on Sunday that Brussels would make a decision on his Brexit deal at the end of this week.