In February court documents obtained by PEOPLE, Orianne, 43, claims her estranged husband, 46-year-old investment banker Charles Fouad Mejjati, fraudulently coerced her into signing a marital settlement agreement and giving him the Miami Beach mansion the couple called home.
Miami-Dade County property records reveal Orianne paid $8.4 million for the residence in 2012, one year after she married Mejjati and four years after her $46.68 million divorce from Collins – the biggest in British legal history at the time.
Then, in June 2015, Mejjati purchased the home from Orianne for just $100, sales information shows. But Orianne's Jan. 19 filing states "no quit claim deed was, to the wife's knowledge, ever presented to the wife" and she didn't agree to the sale.
According to her divorce petition, Orianne claims she was attempting to recover from an unsuccessful spinal and neck surgery that left her partially paralyzed and unable to walk when Mejjati "embarked on a campaign" to intimidate her into signing the marital settlement agreement. (She has since regained movement and is able to walk with the help of a cane.)
While Orianne was under the influence of pain killers prescribed to treat her "constant extreme pain," Mejjati allegedly threatened to make false statements about Orianne that would cause "social embarrassment" and the loss of custody of their son, Andrea, 4, her court documents claim.
The jewelry designer also alleges the agreement is "unfair on its face, and is unconscionable" since the terms would give Mejjati the "majority of the marital assets" in addition to half of her "premarital, non-marital residence located in Switzerland with a very substantial value."
Orianne is asking the court to set aside the agreement (which she claims "has not been adopted by any court order"), nullify the deed, dissolve the marriage, determine custody of their son and child support and distribute their assets.
But in a motion attorney Eric Rayman told PEOPLE he filed to ask the court for a conference last month, Mejjati claims Orianne is attempting to "recreate history" and that her accusations are "wholly unfounded" and "nothing more than a thinly-veiled effort to hide the elephant in the room, namely that the Parties entered into a valid and enforceable settlement contract." Of the agreement, Mejjati alleges "that she was the one who first proposed the terms."
In the midst of her legal battle, Orianne and Phil, 65, clarified their relationship status in an interview with PEOPLE last week. "Yes, we are back together!" the musician shared at a press conference for their Little Dreams Foundation in Miami.
The relationship is mentioned in Mejjati's motion, as he claims Orianne "abandoned" their marriage and "resumed her relationship" with Phil in 2014. Still, Mejjati says he assisted the couple "in locating and securing the purchase" of Phil's Miami Beach home and "cared for the three parties' minor children while overseeing" a renovation of the new mansion as Orianne and Phil "vacationed on their yacht in the Mediterranean" last August.
Speaking to PEOPLE, Phil explained that his reconciliation with Orianne – with whom he shares sons Nicholas, 14, and Matthew, 11 – "wasn't something we wanted to make a song a dance about."
The musician continued: "But obviously when you have children, there's two ways you can go. You can go the nasty way or you can go the nice way, and we always went the nice way ... and we realized we missed each other."
Phil went on to dispel reports that they intend to marry again, saying, "Orianne did an interview in Switzerland and that got back translated from German. She didn't actually say it."
Added Orianne: "I said, 'You never know what the future is going to hold.' I never said, 'Yeah, we are going to get married.' It was like a mistranslation."
That doesn't mean a second wedding for the pair isn't in the cards, though. "It's not impossible – it just hasn't been discussed," Phil told PEOPLE. "We are still enjoying living in a house together and changing light bulbs."
Reporting by BECKY RANDEL