Barrister Kaly Kaul has been hauled up before a High Court judge over remarks made during the War Crimes trial.
Kaul - briefed in the case by her ex-husband Martin Lee, a solicitor acting for defendant Anthony Sawoniuk - incurred the wrath of Mr Justice Potts by revealing to the jury that her client had had his bail revoked.
The decision to withdraw bail from Sawoniuk, 78, was taken on March 25 as the eight-week trial approached its conclusion.
It is not unusual for a defendant to be taken into custody towards the end of a trial, but juries rarely hear of it.
She told the jury Sawoniuk apologised for leaving the court on several occasions during that day's evidence to go to the toilet, because he was upset at having his bail withdrawn.
Clegg later told the jury they had "heard something they should not have".
He said: "We are confident you will put it out of your mind as a relevant factor in this case and not allow it to influence you."
Mr Justice Potts waited until the end of the trial to deal with the matter. It is understood he accepted profuse apologies from Clegg issued on behalf of his junior.
Kaul, of 1 Middle Temple Lane chambers, is an experienced criminal barrister, called to the Bar in 1983. Up until about six months ago she was at 3 Gray's Inn Square. One silk described her as "extremely hard working".
A barrister estimated she could earn as much as £100,000 for the high-profile brief.
Martin Lee, who briefed her, is from south London solicitors' Derek Attridge & Co.
Sawoniuk was jailed for life on Thursday after being found guilty of murdering two unnamed Jewish women. He denied the charges and is likely to appeal against the verdict.