New York (CNN) -- Jurors deliberating on the case against four men accused of plotting to bomb a synagogue and Jewish center were sent home early Friday afternoon after it was discovered one of the jurors had a transcript the judge ruled "inadmissable" before the trial began.
The jury, which began their deliberations this week in a federal court in Manhattan, sent U.S. District Judge Colleen McMahon a note marked urgent when one juror discovered she had a transcript of a telephone call that had not been admitted into evidence.
McMahon called an immediate halt to deliberations and questioned each juror individually to ask them what they had read or discussed of the transcript.
The female juror who found the transcript in her binder said it was from an audio recording of a phone call between one of the defendants and possibly his father. The recording was made after the defendant's arrest.
At least two other jurors said they briefly looked at or discussed the transcript before sending a note to the judge.
"Someone has made a pretty inexcusable error ,but we don't know how bad an error it is," McMahon said in court when jurors were not present.
James Cromitie, David Williams, Onta Williams and Laguerre Payen -- from Newburgh, New York -- were arrested on May 20, 2009. They are charged with conspiring to blow up the Riverdale Temple and the Riverdale Jewish Community Center in Riverdale. They are also accused of planning to fire surface-to-air-missiles at a New York National Guard facility.
The jury spent six weeks listening to testimony and undercover tapes made by an FBI informant, posing as a member of a Pakistani terror group. The jury began deliberations Wednesday.
During the judge's questioning of the jurors, it was also discovered that jurors had another transcript for an audio recording the government had not admitted into evidence, although it had not been ruled inadmissable by the Judge.
Attorneys for the defendants claimed they did not know this was going to the jury and would have addressed it.
"The government is entirely responsible for jurors having things in their binders that are not on the list," McMahon said referring to the evidence list.
The U.S. attorney's office and attorneys for the defendants declined to comment.
The jury returns to court on Tuesday.