An Old Bailey jury was told today that watching a BBC documentary about the Royal family and the media could lead to them being sent to prison.
Mr Justice Saunders, who is presiding over the trial of four journalists from the Sun, told the jury that they had to decide their verdict solely on the evidence they heard in court.
He then instructed them that watching the broadcast could be considered contempt of court, "it's a serious matter," he said.
The two-part programme, "Reinventing the Royals," which will broadcast on BBC 2 this evening (19 February) is billed as a "Two-part series about the 20-year battle between the monarchy and the media over personal privacy and public image."
This has caused concern in legal circles at it coincides with evidence being given by Sun royal editor Duncan Larcombe, who is facing charges over allegations that he paid an army officer for pictures of Princes William and Harry while they were cadets at Sandhurst military college.
While the BBC has said there is nothing in the programme that could impact the trial legal sources say that without the broadcaster knowing the full details of the defence case it would be in no position to make an informed judgement on the issue.
Juries are always cautioned not to let outside materials influence their decision however in this case the judge has decided that a specific warning be issued despite the danger, he admitted in court, that telling people not to do something can often have the opposite effect.
As well as being told not to watch either episode of the programme the jury were told to avoid other media coverage of it, and to report if any other juror revealed they had watched it.
Duncan Larcombe and the other five defendants deny all of the charges against them. The trial continues.