The coroner in the Princess Diana inquest has said he may appeal against a ruling blocking the use of statements from paparazzi who refuse to attend.
Princess Diana was being pursued by paparazzi when she died
Lord Justice Scott Baker had said the French photographers' statements could be admitted as evidence.
However, the High Court backed a challenge to this ruling.
The princess, her companion Dodi Al Fayed and their chauffeur Henri Paul died when their car crashed in Paris while being pursued by photographers.
The coroner said the High Court judgement could make it hard to present vital evidence.
The photographers were asked to appear in person at the hearing.
They declined, and the French government has backed their right not to appear.
Lord Justice Scott Baker decided their statements could be read to the jury, in order to allow the evidence to be heard.
But lawyers acting for the family of Mr Paul and for Mohamed Al Fayed, Dodi's father, said they should be able to cross-examine the paparazzi.
They argued that the Coroners' Rules 1984 prevented the admission of purely written evidence unless it was "unlikely to be disputed".
On Tuesday, Judges Lord Justice Thomas and Mr Justice Aikens ruled in their favour.
But Lord Justice Scott Baker said he had immediately and successfully applied for leave to appeal their judgment.
In a statement, he said the judges' decision could "add materially to the length and cost of these inquests", and make it "more difficult" to allow the jury to hear evidence from absent witnesses.
He added that he was "determined to do his utmost to ensure that all relevant evidence is put before the jury".