Stewart lawyer Robert Morvillo said in papers filed in federal court that he would have sought to strike juror Chappell Hartridge had he known about his past.
"These facts, in and of themselves, establish that Ms. Stewart is entitled to a new trial," Morvillo wrote.
The papers also accused Hartridge of seeking money for post-trial interviews. On the day of the guilty verdict, the juror said publicly that he believed the decision was "a victory for the little guys."
Federal prosecutors did not immediately return a call for comment. A telephone number for Hartridge could not immediately be found.
"This is a serious allegation and a serious motion but there is no certainty that Stewart will in the end get a new trial. Even if the judge is convinced that this juror indeed lied she still would have to become convinced that the defense could have had him removed from the jury pool for cause and it's that element that may be tough to prove," says CBSNews.com Legal Analyst Andrew Cohen.
"I don't see how the defense convinces the judge that these alleged misstatements by the juror were material to his ability to judge Stewart fairly and impartially. If anything, defense attorneys might have thought the guy was a good juror for their side had they known in advance about his run-in with the law," says Cohen.
"Even if these allegations are true, I'm not sure that Stewart's lawyers are going to be able to convince this judge in this case that Stewart was denied her right to a fair trial," Cohen says.
Stewart was convicted March 5 along with her broker, Peter Bacanovic, of obstructing justice and lying to the government about her sale of a block of stock in a biotechnology company just before the price dropped.
Stewart's Web site about her legal troubles, marthatalks.com, reports that she has received 35,000 supportive e-mail messages since the verdict was announced March 5.
The homemaking authority is scheduled to be sentenced June 17. She is widely expected to get 10 to 16 months in prison.
Stewart's lawyers said Hartridge was arrested in 1997 after a woman with whom he was living filed an assault complaint. They said Hartridge spent several days in jail before the woman withdrew her complaint because she could not miss work to attend court.
In a juror questionnaire, Hartridge claimed he had never been in court other than for a minor traffic violation, the defense lawyers said.
The defense also said that Hartridge lied on his jury questionnaire by omitting that he has been sued at least three times. It said he also lied by not disclosing that he was once accused of stealing from a Little League group.