By Jim Armstrong, WBZ-TV

BOSTON (CBS) – James “Whitey” Bulger appeared agitated today as testimony in his federal trial focused on what government prosecutors say is his FBI informant file.

Jurors saw three massive binders, roughly the size of telephone books, placed on the witness stand. Department of Justice Special Agent James Marra used the documents in his testimony, which detailed years’ worth of tips Bulger is alleged to have passed on to his FBI handlers.

Prosecutors laundry-listed the many times Bulger and his partner Steven Flemmi met with agents and handed over names of people associated with crimes ranging from drug dealing to murder.

In one such document, an FBI agent wrote that Bulger was aware of rumors on the street that he was cooperating with investigators. The agent wrote that Bulger was dismissive of the claim, since, as Bulger is alleged to have put it, “No one would dare believe he is an informant. It would be too incredible.”

But when Assistant US Attorney Fred Wyshak tried to ask Marra if Bulger was, in fact, an informant, defense attorney Hank Brennan objected and the jury was asked to leave the room.

“Why is it improper for the government to ask about Mr. Bulger as an informant?” asked Judge Denise Casper.

Defense attorneys will argue that FBI Agent John Connolly was corrupt and he made up Bulger’s FBI files.

Prosecutor Fred Wyshak telling the judge, “I’m not going to engage in the fiction in my questioning that Mr. Bulger was not really an informant.”

WBZ NewsRadio 1030’s Lana Jones reports

But Casper sustained the objection, the jurors were brought back in, and the question about whether or not Marra would call Bulger an “informant” went unanswered.

But in the heat of that argument, before the jury came back, several people in court heard Bulger say under his breath words to the effect of — that’s because I’m not a [EXPLETIVE] informant. The judge did not appear to hear him.