A suspected bugging device may have been found in the home of Princess Diana, the inquest into her death has been told.
Princess Diana died in a Paris car crash in 1997
Security expert Grahame Harding said he had searched Diana's palace rooms four times in four months in 1994 and on one occasion a signal was found.
The princess believed people had been assigned to spy on her and had talked of "dark forces", the jury heard.
Diana and Dodi Al Fayed died after a car crash in Paris on 31 August 1997.
Mr Harding said the possible device was discovered in a wall dividing Diana's rooms from one used by Prince Charles.
"It could have been a number of things ... at that time I believed it was a particular device," said Mr Harding.
He explained that there was no evidence that the wall had been altered and he could not get access to the room behind the wall.
Mr Harding said when he did another sweep of the wall a few days later the transmission had gone.
When questioned again, Mr Harding agreed the readings could have come from a number of things such as a radio or a mobile phone.
The inquest also heard about Diana's concerns that a team was in place watching and listening to her.
Details of an October 1994 meeting the Princess had with the head of royalty and diplomatic protection was read to the inquest.
The written note stated: "She had been told without any doubt that five people from an organisation had been assigned full-time to oversee her activities including listening to her private telephone conversations."
Asked by Nicholas Hilliard, representing the coroner, about his statement to the Metropolitan Police that Diana talked of "dark forces" when talking about a possible bug, Mr Harding replied: "They were words she used to me 'there are dark forces' and never really expanded on that in any way."
Earlier the inquest heard from Rodney Turner, a personal friend of the Princess, who said her relationship with Mr Fayed had ended a few weeks before the fatal crash.
Mr Turner, an HR Owen director, struck up a friendship with the princess after he started supplying her with BMW cars in 1995.
Asked about Diana's relationship, Mr Turner told the High Court in London: "What she said to me was that it was all over, which was really a shock for me."
He said the princess told him: "Don't fuss, don't fuss. It's all over. I've had a wonderful time."
Mr Turner's conversation with Diana took place in early August 1997, and later that same month she and Dodi were pictured on holiday together on a yacht.
Michael Mansfield QC, counsel for Mr Al Fayed's father Mohamed, asked Mr Turner whether the princess was simply trying to avoid talking about the relationship because she knew he did not approve of it.
"You could be absolutely right," the witness replied.
Mr Turner said Diana had never told him "she was intending to get married to one particular person".
He said the princess was "very happy and extremely positive" in the period before her death.
In 1993, Diana wrote a letter to her butler Paul Burrell saying she believed the Prince of Wales wanted her dead.
When he was asked about it, Mr Turner said: "Standing here today, what I find absolutely amazing is the letter that Paul Burrell produced (that) was a bombshell to all of us and it was something she never discussed."
He said Diana once joked about the potential threat to the Royal Family posed by the IRA, saying: "If it's not the IRA, it's my husband."
It was reported on Monday that Diana's former boyfriend, heart surgeon Hasnat Khan, would give evidence at the inquest.
But a spokesman for the hearing would not confirm whether he would be called.
Mr Khan has never publicly discussed their relationship.