His father, known for his dazzling wealth and development work around the world, died in Lisbon, the seat of the Ismaili Imamat, at age 88 on Tuesday.

Reuters reported that the funeral is expected to take place in Portugal s capital "in the coming days", as soon as arrangements are finalised.

The world s Ismaili community, a branch of Shi ite Islam, comprises around 15 million people who live in Central Asia, the Middle East, South Asia, sub-Saharan Africa, Europe and North America.

Born on Oct. 12, 1971, the U.S.-educated, Swiss-based Rahim is the eldest son of the Aga Khan IV and his first wife, Princess Salimah - née Sarah Croker Poole, a British ex-model. The couple had a daughter and two sons together.

Rahim has two sons through his marriage with former American fashion model Kendra Spears.

He has served on the boards of many agencies of the Aga Khan Development Network and chairs its Environment and Climate Committee, according to the website.

"Prince Rahim has been particularly concerned with the AKDN s drive to protect the environment and mitigate the effects of climate change," it said, also highlighting his attention to the institution s work "addressing the needs of those living in the greatest poverty".

Set up in 1967, the AKDN group of international development agencies employs 80,000 people helping to build schools and hospitals and providing electricity for millions of people in the poorest parts of Africa and Asia.

Aga Khan IV mixed his development work with private business, owning for example in Uganda a pharmaceutical company, a bank and a fishnet factory.