A plane has landed in Germany with a fully vaccinated dead man on board who later tested positive for COVID-19 and the circumstances surrounding his death still remain a mystery.

The unnamed 51-year-old man, who was born in Russia and lived in the German state of Schleswig-Holstein, was found dead when flight PC1043 landed in the German city of Hamburg.

The Airbus A320 operated by Turkish low-cost airline Pegasus Airlines had taken off from Istanbul and landed at its destination at around 1 pm on Monday, 25th October.

Forensic pathologists performed a postmortem on the body and concluded that the man had probably died mid-flight.

They noted he tested positive for COVID-19. However, as he was reportedly fully vaccinated, it is unclear if he had presented any symptoms during his final days.

Turkey is considered by Germany to be a “high-risk” country for COVID-19, and travellers must be fully vaccinated, have recovered from COVID-19 or present a negative test result.

Local media did not report whether other passengers noticed the man was dead during the three-hour-and-twenty-five-minute flight

It was not reported if he was travelling with anyone else, though local media seemed to imply he was travelling alone.

According to the local newspaper Hamburger Abendblatt, the man had suffered from several serious prior illnesses, which were not specified.

The passengers sat in the his vicinity and the cabin crew were ordered to report to the health department.

The official cause of the man’s death is not clear.