Chaleo Yoovidhya, the reclusive Thai billionaire who made his fortune in the pulse-fluttering tonic known as Red Bull, died March 17 at a hospital in Bangkok.

Few details about the man Forbes magazine ranked as the world’s 205th richest person have been confirmed in news reports. Announcing his death, the Thai publication the Nation claimed Yoovidhya had not given an extensive interview in more than 30 years. Accordingly, various news outlets have reported his age as either 81, 89 or 90. No cause of death has been determined.

What is known about Yoovidhya is that he was born to poor Chinese immigrants in the northern Thai province of Phichit.

Before he became worth an estimated $5 billion, he had been employed as a bus conductor, fruit vendor and duck farmer.

In 1962, he founded T.C. Pharmaceuticals, a manufacturer of antibiotics and cosmetics. One of his company’s products was a syrupy energy tonic called Krating Daeng. The beverage was sold in pharmacies as a stimulant for day laborers, weary long-haul truckers and rickshaw drivers.

During a trip to Thailand in 1982, an Austrian toothpaste salesman named Dietrich Mateschitz was amazed by the jet-lag-eliminating properties of Krating Daeng.

Yoovidhya and Mateschitz formed a business together after tinkering with the recipe — it was Mateschitz’s idea to carbonate it and sell it in a slim silver can. Red Bull was released in 1987.