An inquiry will be held into the fatal helicopter crash off Sumburgh, which claimed the lives of four people in August 2013.
In a statement, the Crown Office says the investigation into the crash “has reached a significant stage”.
“Crown Counsel have instructed that a fatal accident inquiry be held into the deaths of Duncan Munro, Sarah Darnley, Gary McCrossan and George Allison, who were passengers being transported from North Sea oil and gas platforms to the mainland.
“In coming to this decision Crown Counsel have considered the available evidence, the recommendations of the COPFS [Crown Office and Procurator Fiscal Service] Helicopter Incidents Investigation Team, and expert opinion.
“The investigation by the police, with officers working closely with the COPFS Helicopter Team, has been complex and challenging.
“COPFS will now work closely with the Scottish Courts and Tribunals Service (SCTS) to make suitable arrangements for holding the inquiry.
“COPFS will continue to keep the relatives of the deceased informed of significant developments.”