Lawyers for Ghislaine Maxwell said the overturning of Bill Cosby's 2018 sexual assault conviction justifies throwing out sex trafficking and other charges stemming from her relationship with the late financier Jeffrey Epstein.
Mr Cosby, 83, was released from prison on Wednesday after Pennsylvania's Supreme Court said a prosecutor's 2005 agreement not to charge him with drugging and assaulting Temple University employee Andrea Constand meant the actor and comedian should not have been charged a decade later.
Today, in a letter sent to District Judge Alison Nathan in Manhattan, Ms Maxwell's lawyers said the British socialite's case was similar to Bill Cosby's because she had been immunised under Epstein's 2007 non-prosecution agreement.
They said this supported dismissing four charges from Ms Maxwell's eight-count indictment, which covers alleged crimes from 1994 and 2004 and could subject her to 80 years in prison.
Ms Maxwell, 59, has pleaded not guilty.
"As in Cosby, the government is trying to renege on its agreement and prosecute Ms Maxwell over 25 years later for the exact same offences for which she was granted immunity," her lawyers said.
"This is not consistent with principles of fundamental fairness."
The office of US Attorney Audrey Strauss in Manhattan declined to comment.
Epstein struck his agreement with federal prosecutors in Florida in exchange for pleading guilty to state prostitution charges.
Judge Nathan ruled in April that the agreement did not bind prosecutors in Manhattan. She also rejected Ms Maxwell's claim that it covered accused co-conspirators like herself.
The 2005 decision not to charge Mr Cosby cleared the way for his testimony in a civil lawsuit by Ms Constand, which ended in a $3.36 million (€2.8m) settlement.
Pennsylvania prosecutors later used incriminating testimony Bill Cosby gave to build a new criminal case.
The Pennsylvania court said they could not, and set the actor free after he had served more than two years of a possible 10-year sentence.
On Wednesday, one of Ms Maxwell's lawyers, David Markus, argued in an opinion piece in New York's Daily News that Cosby's release justified ending his client's prosecution.
He said it was unfair for prosecutors to use her testimony in 2016 from a civil lawsuit against her by Epstein accuser Virginia Giuffre to build their case, and that a jury should reject their "flimsy and stale charges."
On Thursday, prosecutors said Mr Markus' opinion violated a court rule against lawyers making "extra judicial statements" that could taint the jury pool, and asked Judge Nathan to order him to comply.
