A jury was told not to watch a TV programme and a journalist agreed he didn't think it mattered that a source was a serving soldier at London's Old Bailey today.Mr Justice Saunders, who is presiding over the trial of four Sun journalists, an army officer and his wife, told the jury that if they watched a BBC documentary about the media and the royal family they could be held in contempt of court and potentially be sent to prison. The programme "Reinventing the Royals" being broadcast on BBC 2 on Thursday is billed as a "two-part series about the twenty-year battle between the monarchy and the media over personal privacy and public image". This has caused concern in the court room as 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 information about and pictures of Princes William and Harry while they were cadets at Sandhurst military college.The judge told the jury that although he had not seen the documentary there was a chance that matters relating to the trial might be discussed. As there would be no possibility of the defence challenging anything said on television in court he had to take the matter very seriously. He therefore gave the jury a written direction not to watch the programme, avoid any media coverage of it and inform the bailiff if any of their number admitted they had watched it.Later in the day Larcombe gave evidence in his own defence, and asked if it mattered that his source for a number of stories was a serving soldier replied "not in my mind, no". He also testified that "If you were a source for the Sun you were always taking a risk", saying people could be shunned or sacked for speaking to the paper. He also denied that he ever thought Hardy was committing a criminal offence or obtaining the picture was a betrayal of his public duty as he believed all of the information obtained, including a picture of Prince William in a bikini was "in the public interest".Appearing in court with Larcombe are former Sun chief reporter John Kay, army officer John Hardy, his wife Claire, Sun deputy editor Geoffrey Webster and executive editor Fergus Shanahan.All of the defendants deny all of the charges, the trial continues.