Detectives investigating the circumstances that led to the Shoreham Airshow crash have applied to the High Court for access to key information relating to the accident.
A Hawker Hunter jet plane crashed onto the A27 last August, killing 11 men.
Sussex Police want to see 'protected material' that is held by the Air Accidents Investigation Branch (AAIB), including cockpit recorders and footage, witness accounts, expert reports and documentation.
The issue has gone to court because aviation law blocks access to some material. The Lord Chief Justice Lord Thomas and Mr Justice Singh will be asked to approve the release of the evidence today.
The pilot of the Hawker Hunter jet, Andrew Hill, was thrown clear from the aircraft and suffered life threatening injuries. He was later discharged from hospital. He was voluntarily interviewed about the accident under caution by Sussex Police.
An AAIB spokesperson - at a pre-inquest review in March - said that the organisation had released three special bulletins into the crash, and that a full report is due to be published by the end of this summer.
Also at the hearing was Detective Chief Inspector Paul Rymarz, who said that there was "very good liaison" between the police and the AAIB which had "sought to co-operate to the maximum extent possible under the regulations".