Initial reports of the July 2 fatality revealed that the man had fallen ill and was being collected by a CHC-owned Super Puma search and rescue helicopter from Statoil's Troll A platform to be taken to Bergen, Norway.

London's The Telegraph recently offered some new insights on the man's mysterious fall. There were two pilots, a rescue officer, a lift officer and a medic aboard the helicopter at the time.

"Accident investigators are probing the circumstances of the man's death, but it is believed an emergency door opened during the flight and he plunged through it," the newspaper reported.

"Search and rescue pilots immediately looked for the man and his body was found within an hour."

"During the flight, the man climbed out of the helicopter's emergency exit," police officer Thomas Soerensen was reported to have said.

"He fell into the sea and we believe he died immediately."

Jake Molloy, regional organiser for offshore union RMT, told the newspaper he had "never come across this type of scenario" in his 34 years in the oil and gas industry.

The dead man's name has not yet been released, but reportedly he is a 37-year-old Swede employed by Kaefer Energy.

Kaefer CEO Bard Bjorshol reportedly said the company was in contact with families to provide help.

"For our employees, especially on the platform, Kaefer Energy has been present with representatives from the company's management," he said.

"(We have) also assisted with medical staff, priest and an additional platform manager."

Investigations are continuing.