A juror has been discharged in the long-running trial of the alleged Three Musketeers terror cell for "jokingly" asking whether an officer in the case was single.
The defendants, from the West Midlands, are accused of plotting a Lee Rigby-style attack on British soil before their arrests last summer.
Naweed Ali, 29, Khobaib Hussain, 25, both of Sparkhill in Birmingham, Mohibur Rahman, 32, and Tahir Aziz, 38, of Stoke-on-Trent have denied preparing terrorist acts.
They claim a partially constructed pipe bomb, meat cleaver and other incriminating evidence found by MI5 in Ali's car was planted by an undercover officer.
The four-month Old Bailey trial was halted as Mr Justice Globe was about to finish his summing up and send jurors out to begin deliberating verdicts.
The senior judge discharged the female juror, who cannot be identified, and then explained his reasons to the remaining 11 men and women.
He said the issue arose following an inquiry from a news reporter who "overheard" something.
He told jurors: "The information that had recently been given to me was that one amongst your number had said that DS (Ryan) Chambers was attractive and another among you had then spoken to the court usher and on more than one occasion had asked the court usher to find out whether DS Chambers was single."
The judge said one of the jurors in question had admitted finding him "attractive" but had not expressed any interest in finding out whether he was single but the other juror had "jokingly" asked whether he was.
He went on: "Although the juror who found DS Chambers attractive did not want an inquiry to be made of the usher none the less the other juror went ahead and asked the usher."
Afterwards, the juror who was discharged was "not candid" about what she had done while the other had said she would "definitely" remain true to her oath.
The judge reminded the jury that DS Chambers was among a number of officers to face criticism by the defence.
He said: "One of the issues you are going to have to consider is his credibility."
Mr Justice Globe suggested there was a "very strong possibility" one or more of the remaining jurors might have known about the woman's inquiries about DS Chambers but had failed to speak up.
He told them: "To put it mildly, I'm disappointed that I was not given that information.
"I have had to ask myself if it is so important that I should not allow you as a group to continue considering this case.
"I have come to the conclusion I have to draw a distinction between the person I have had to discharge and the rest of you for this reason: the person who made this inquiry is most at fault and more than once and also she has not been candid with me. That makes it a far worse situation in terms of trust."
He went on to say that if any of them had any other information he needed to know about they should to come forward "as soon as possible".
The judge said: "I asked further questions as to whether there had been any other contact with DS Chambers in any other way or asking for any information from him and I have been told in very clear terms that no such request was made."
But he explained how the discharged juror's answers to questions had differed from information received from the usher and the other juror.
"I am left with the situation that her answers are really unsatisfactory.
"She has not accepted that she was trying to find out from the court usher on more than one occasion whether DS Chambers was single," he said.
"Even if you, superficially, find someone you don't know attractive, you really shouldn't let that get in the way of your fact-finding."
The judge said any attempt to find out information about that person is "wholly wrong", adding: "What that person was thinking about speaking to the usher in asking to get personal information about DS Chambers, I really don't know."
He told remaining jurors the woman had "not been prepared to be candid with us" and said: "I simply cannot trust her to carry out her responsibilities."
The jury was told to return at 10.30am on Monday to continue summing up before he sends them out to begin their deliberations.