THE Scottish Government is taking legal action to access the black box from a helicopter crash that killed a Hampshire man and three others.
George Allison, 57, of Winchester, died after a Super Puma helicopter crashed into the North Sea in August 2013.
The Air Accidents Investigation Branch said it found no evidence of technical failure in the aircraft, which was carrying 16 passengers and two crew.
But the Crown Office is also investigating and is trying to access cockpit voice recordings currently held by the AAIB.
In what is being described as a rare legal move, the Crown is expected to petition the Court of Session with the aim of recovering material which is held by the AAIB.
Blackbox recorders are normally retained by AAIB during safety investigations, but a court can rule they should be handed over if it considers it to be in the public interest.
The crash en route to Sumburgh Airport also claimed the lives of 45-year-old Sarah Darnley from Elgin, Moray, Gary McCrossan, 59, from Inverness and Duncan Munro, 46, from Bishop Auckland in County Durham.
A memorial service was held at the airport last weekend to mark the first anniversary of the crash.
The families of those who died have been informed of the latest development. No date has yet been set for a Court of Session hearing.
A Crown Office spokesman said: ''Following a helicopter crash off Sumburgh on 23 August 2013 in which four people died, Crown Office began an investigation into the cause of the deaths.
''The investigation is ongoing and the families of those who died will continue to be updated in relation to any significant developments.''
An AAIB spokesman said: ''Regulations allow for the release of this type of information if a court decides it is in the public interest to do so. The court has yet to make its decision in this case.''