Greece's last King Constantine II has died aged 82, his doctors say.

He passed away in an intensive care unit in a private hospital in Athens late on Tuesday, the Associated Press reports citing hospital staff.

Constantine II ascended to the throne in 1964 during a turbulent period in Greek history that culminated in a military coup three years later.

He was soon forced to flee abroad following an unsuccessful counter-coup. The monarchy was abolished in 1973.

Constantine II was later stripped of his Greek citizenship.

He was married to Princess Anne-Marie of Denmark. The couple had five children.

In 2002, he and other family members received compensation for their former property in the country.

A keen sailor, Constantine II won gold in a team event at the 1960 Olympics in Rome.

He also later served on the International Olympic Committee.