MI6 were not keeping files on Princess Diana or Dodi Al Fayed, the inquest into their deaths has heard.
Princess Diana was killed in a car crash in Paris in August 1997
A female MI6 manager, named only as Miss X, told the High Court that searches she made of an electronic database found no information on them.
The hearing has been cleared of all those not directly involved, in order to protect the identity of the witness.
Last week the former head of MI6, Sir Richard Dearlove, denied the intelligence service murdered Diana.
Journalists and members of the public were moved to a nearby annexe so they could hear the witness's voice, but not see her.
Miss X said the Secret Intelligence Service (SIS) - known as MI6 - kept a card on Dodi Al Fayed's father, Harrods owner Mohamed Al Fayed, but nothing more detailed than that.
Ian Burnett QC, counsel for the coroner, asked Miss X about Diana and the princess's boyfriend Dodi: "No cards for either and no files for either?"
She replied: "Absolutely correct."
Mr Burnett asked: "If for the sake of argument there had been any plan at all involving Diana, Princess of Wales and Dodi Al Fayed would that have been drawn up by your searches?"
"Yes, there was absolutely no plan whatsoever," Miss X responded.
Mohamed Al Fayed claims the crash, in which Diana, Dodi and their driver Henri Paul died, was part of a murder plot by MI6 and the Duke of Edinburgh.
Miss X searched the files as part of former Metropolitan Police Commissioner Lord Stevens' investigation into the deaths, named Operation Paget.
Asked about any references to the duke, she told the inquest: "I would just like to say at this stage, sir, we don't hold one, either files or cards on the Royal Family. I could do a search on all of them."
Miss X said she had found a card on Mohamed Al Fayed which had been created in the 1980s, but there were no entries for 1997.
She checked for photographer James Andanson - believed by Mr Al Fayed to be the driver of a mystery Fiat Uno linked to the crash - but he was not found on the system.
There was also no record of the security services using a Fiat Uno in Paris, the jury was told.
Two messages on the SIS's electronic telegram system related to the crash, but they were dated 5 November 1997, after the incident.
Miss X suggested a plan claimed by former British spy Richard Tomlinson to assassinate a Balkan leader in the early 1990s was in fact a memo that had been rejected before it could be documented.
Michael Mansfield QC, representing Mr Al Fayed, suggested the memo had gone to the head of a different department, outside the Balkans section at MI6.
Miss X was asked whether there was MI6 guidance on when force or threat of force would be acceptable.
She replied: "We do not go around killing people. It is simply not done."
The hearing continues.