Mexican drug kingpin Joaquin "El Chapo" Guzman. Picture: United States Drug Enforcement Administration via AP

Washington - At the start of every jury trial, it's standard practice for the presiding judge to give jurors a set of preliminary instructions.

US District Court Judge Brian Cogan took it a step further during the high-profile trial of Mexican drug kingpin Joaquin "El Chapo" Guzman.

Trial transcripts recount that Cogan gave three directives to the jury just before 5 p.m. on January 30, immediately after the prosecutor concluded the closing argument. They were the same rules he had repeated most, if not all, days during the three-month trial:

"Stay away from any media coverage."

"Do not communicate about this case either among yourselves at all or with anyone."

"No postings, no research on the case, no Internet."

On Wednesday, Vice News reported that at least six jurors ignored Cogan's orders, perusing social media, surfing the Internet and discussing the discovered information. According to the outlet, reporter Keegan Hamilton learned of the revelations during a video interview with an individual who claimed to be an El Chapo juror.

Any judge would be loath to overturn a conviction, or order a new trial, in such a high-profile case (particularly where extraordinary government resources were brought to bear, partly during the month-long government shutdown).

But if true, the claims of widespread misconduct pose a viable threat to the conviction secured by federal prosecutors a week ago.

"It's honestly shocking," attorney Jeffrey Lichtman, who represented Guzman, said in an email to The Washington Post on Thursday. He confirmed the defence plans to file a motion requesting the judge question the jury.

The US Attorney's Office in the Eastern District of New York declined to comment on the case, which is scheduled for sentencing on June 25.

The federal rules of evidence are fashioned so a verdict is based on evidence presented in the courtroom and jurors receive only admissible information that helps establish the guilt or innocence of the accused.

"There's a lot that can prejudice a juror," said Duncan Levin, a former federal prosecutor. "There could be evidence that didn't come in at the trial, sensationalistic articles about the defendant's guilt. There are all sorts of things that jurors shouldn't be looking at."

In Guzman's case, he said, there were "so many issues."

According to the Vice report, several jurors digested the very type of information the rules try to preclude.

"You know how we were told we can't look at the media during the trial? Well, we did," the juror told Vice.

Mobile devices were banned from the courtroom, but journalists - including Hamilton - updated social media feeds during breaks in the testimony. Often, these posts mentioned details that could be detrimental to the defence and developments that took place outside the presence of the jury.

The juror told Vice several people read information that was kept from the jury.

At one point, Cogan announced he would interview jurors individually about whether they had read the news, in violation of the court's order, according to the Vice account. The juror told Vice he warned others about the judge's planned inquiry.

During the Vice interview, the individual shared detailed notes with Hamilton that were allegedly taken during the trial and kept against the court's instructions. The juror also said that they considered Guzman's sentence, specifically whether he would serve time in solitary confinement, something jurors are not permitted to do.

Levin said it's "presumptively unfair" if the jurors disregarded Cogan's orders.

"When we weigh government hardships versus the right to a trial that is fundamentally fair, we have to tip toward fundamental fairness every day of the week," he said. "You're entitled to due process whether you're a regular defendant or the most hated man in the world."

The Vice allegations are not ones a judge can ignore, which makes it likely Cogan will order additional fact finding and interview the jurors to determine whether misconduct occurred. If the answer is yes, the question will be whether the verdict was impacted.

Should an examination of the jurors take place, Lichtman hopes they answer honestly.

"Whatever anyone thinks of Joaquin Guzman, he deserved a fair trial," he said.

The Washington Post