They claim they asked for a $250,000 pretrial retainer soon after her July 2020 arrest by the FBI on charges of sex trafficking. Around half of it was paid promptly.
HMF, a high-profile Denver firm which previously defended Kobe Bryant in his Colorado sexual assault case, emailed Maxwell asking for updates regarding the $140,000 they owed. Maxwell reportedly ignored the emails.
"As 2021 progressed, Ms Maxwell fell consistently behind on her obligations to HMF. When HMF raised concerns, Ms Maxwell routinely assured the firm that he would satisfy the outstanding invoices," the wrote in the filing to the Denver District Court, first spotted by Australian podcaster Jen Tarran.
"To keep HMF from withdrawing, Mr Maxwell made a handful of sporadic payments."
As her November 2021 trial neared, HMF asked for a larger $1 million retainer in "recognition that Ms Maxwell's trial would be a complex and extended ordeal that would require HMF to advance substantial costs, divert the firm's resources from other matters, and require turning away other potential clients."
When that was not paid, on November 5 they threatened to end their representation. Maxwell followed up by reiterating "the commitment we as a family have made to honour the fees due and requested by you both in good faith and as a binding commitment."
Maxwell allegedly told the firm that Ghislaine's husband at the time, Borgerson, controlled Maxwell's assets and was responsible for delaying payments to the firm.
The legal firm claims tech entrepreneur Borgerson formed two limited liability companies and used Maxwell's money to buy two high-end condos in Boston and other properties in Massachusetts and New Hampshire in an attempt to shelter her assets.
In her second attempt to secure bail while awaiting trial, the 60-year-old offered the New York federal court a $28.5 million (46 million NZD) bond package.
It was revealed that soon after their 2016 marriage she had put the majority of her $20.2m assets into a trust controlled by Borgerson, which was now worth $22.02m.
Prosecutors said Maxwell's transfer of money to her husband showed her ability to "hide her true wealth" and claimed she had not been truthful about her assets in her initial financial disclosures.
The firm agreed not to drop her case. "HMF, relying on Mr Maxwell's commitment, continued to devote all necessary resources to Ms Maxwell's defence," the attorneys wrote.
After Maxwell's trial ended in a guilty verdict in December, more than $950,000 was due. In mid-January, Maxwell paid HMF $143,500, but the rest, the firm claims, is still outstanding despite "assurances" the money would be sent.
When HMF informed Maxwell in prison that they planned to withdraw their services ahead of her sentencing hearing, the socialite reportedly pleaded with them to stay on her case.
"HMF has been damaged as a result of Mr Maxwell's fraud in an amount to be proved at trial," the firm finished by saying.
They are also suing Borgerson for "wrongfully encumbering Maxwell's assets, joint marital assets, and/or assets committed to fund her defence, impairing her ability to perform her obligations."
They claim Borgerson and Maxwell "shared the motive of protecting those assets from creditors including HMF."
Kevin Maxwell, 63, was acquitted in the 1990s of charges relating to financial crimes connected with the business practices of his father, publishing tycoon Robert Maxwell. He later declared bankruptcy.
He supported his sister at trial, sitting alongside siblings Ian, Christine and Isabel at the Thurgood Marshall courthouse in Manhattan.
HMF attorney Christopher Montville, who represents the firm in the case, did not respond to request for comment.
Maxwell is serving a 20-year-sentence at a low-security federal prison in Tallahassee, Florida. She has retained a new lawyer for her appeal.
