Saudi Arabia's Prince Saud al-Faisal, who was the world's longest-serving foreign minister, has died, family members and a foreign ministry spokesman said late Thursday.

Prince Saud, who was born in 1940, was one of the highest profile members of Saudi's ruling elite and steered the diplomacy of the world's leading oil exporter for four decades before stepping down in April for health reasons.

The prince oversaw Saudi Arabia's emergence as a major diplomatic player, facing successive regional crises and maintaining a focus on relations with the West.

Nawaf al-Faisal, a relative, announced the death on Facebook, while a foreign ministry spokesman also confirmed the death on Twitter and expressed condolences.

"I wish I could deny the rumour of the news of your death," the spokesman Osama Nugali tweeted.

Prince Saud's nephew Saud Mohammed al-Abdullah al-Faisal also acknowledged the death of the veteran diplomat.

"May God accept him in paradise," he wrote on Twitter.