Convicted former State Sen. Vincent J. Fumo asked for a new trial yesterday, saying that he had just learned that a juror unfairly knew prejudicial facts about him, including that Fumo has once before been convicted of corruption.

Fumo's defense team said a freelance reporter for Philadelphia Magazine had discovered this from interviewing members of the Fumo jury after it convicted the once-powerful Democrat in March of 137 counts of conspiracy, fraud, tax violations, and obstruction of justice.

The defense also said that the reporting by Ralph Cipriano suggested that many of the jurors had disobeyed a judge's order that they not follow media accounts during the marathon trial.

The newest member of Fumo's team, lawyer Samuel Buffone of Washington, asked that the judge interview the jurors about Cipriano's reportage and then grant Fumo a new trial.

Assistant U.S. Attorney Robert A. Zauzmer, who prosecuted Fumo along with Assistant U.S. Attorney John J. Pease, declined to comment. They are expected to file legal papers fighting the defense motion within a few days.

Buffone filed the motion seeking a new trial as the days count down to Fumo's scheduled July 14 sentencing. Sentencing guidelines call for Fumo, 66, to go to prison for 21 to 27 years, but U.S. District Judge Ronald L. Buckwalter is free to impose any sentence he wants.

The defense challenge is a serious pleading but faces a high bar to succeed, legal experts said yesterday.

To win a new trial, Fumo would not merely need to persuade Buckwalter to hold a hearing and to decide that jurors had picked up forbidden information outside the courtroom. The judge would also have to rule that any juror misconduct was so grievous as to have denied Fumo a fair trial.

After a 22-week trial, a jury of 10 women and two men convicted Fumo of a $4 million fraud on the state Senate, a South Philadelphia charity, and a maritime museum on Penn's Landing. The jury also found that Fumo had orchestrated a digital coverup in an attempt to thwart the FBI investigation.

According to the defense motion, Cipriano told Fumo defense lawyer Dennis J. Cogan late last month that six Fumo jurors had spoken with him since delivering their sweeping verdict.

One juror volunteered to Cipriano that a fellow worker had said during a job-site conversation on a trial off-day that Fumo had previously been convicted of corruption. In 1980, a federal jury found Fumo guilty of placing "no-show" workers on the state payroll, but the conviction was swiftly overturned by the judge.

The same juror also said the coworker had told him that a key figure in the Fumo saga, disgraced maritime museum chief John S. Carter, had been convicted of fraud and imprisoned.

One part of the complex case against Fumo alleged that he had defrauded the Independence Seaport Museum of $115,000 in large part by taking lengthy yacht cruises at museum expense.

Prosecutors argued at the trial that Fumo and Carter conspired together to permit Fumo to enjoy the yacht vacations. But Buckwalter rejected their request to also tell the jury that Carter pleaded guilty in 2007 to looting the museum of $2.5 million.

The judge kept this out of bounds because Fumo played no role in that theft.

Jurors were instructed to alert the judge if they inadvertently heard any information about Fumo outside of court. But the juror reportedly failed to do this.

The motion did not name any of the jurors interviewed. Cipriano and Larry Platt, the editor-in-chief of Philadelphia Magazine, declined comment. The article is to be published in a month, Platt said.

Cipriano worked for 11 years as a reporter for The Inquirer before leaving the paper in 1998. He covered the Fumo trial as a blogger for the Beasley law firm in Philadelphia.

Another part of the defense had to do with the Twitter controversy that flared at the end of the trial.

Right before the jury announced its verdict, the defense learned that one juror, Eric Wuest, had posted several messages about the case, using Twitter and Facebook.

After Wuest was gently questioned by the judge, prosecutors, and defense lawyers, Buckwalter ruled that the postings were innocuous and his conduct harmless, even though he had violated court orders that jurors not discuss the case with anyone.

The news of Wuest's postings was broken by a Philadelphia TV station on the night before the jury delivered its verdict. According to the motion yesterday, a juror told Cipriano that the entire panel was well aware of Wuest's activity when it reassembled.

This, the motion said, suggested that the jury as a whole had ignored the judge's order that they not read newspaper coverage or follow TV and radio accounts of the trial. The result, the defense said, was that the jury was likely exposed to months of "slanted and hyperbolic media coverage."

Dan Richman, a law professor at Columbia University and former federal prosecutor, said defense lawyers in "well-publicized trials involving well-resourced defendants" were increasingly demanding that judges explore whether jurors had been improperly exposed to damaging information.

He said the trend put judges and jurors in a tough spot. For jurors, Richman said, it could mean they had to undergo the burden not only of jury service but also of "post-service investigation."

Gregory A. Paw, a former federal prosecutor who is now a defense lawyer with the Pepper Hamilton firm in Philadelphia, cautioned that such appeals are "frequently made, but relief is seldomly granted."