Renowned neurologist Atthasit Vejjajiva, the father of former prime minister Abhisit Vejjajiva, died at 87 on Wednesday, according to Mr Abhisit.
Mr Abhisit said his father died of leukemia after two years of treatment at Ramathibodi Hospital.
A royally-sponsored bathing ceremony will be held at Wat Thep Sirintharawat today, he said.
Dr Atthasit served as a former deputy public health minister, was a former president of the Royal Society, a former president of Mahidol University, and a former senator.
While dean of Ramathibodi Hospital's faculty of medicine, he initiated a project establishing its Advanced Diagnostic Imaging Centre.
Born on Nov 3, 1935, he was the 7th of 10 children of Kosit and Supian Vejjajiva.
His elder brother, Nissai Vejjajiva, was a former diplomat and the father of Suranand Vejjajiva who served as a former PM's Office minister during the Thaksin Shinawatra government.
Dr Atthasit married Dr Sodsai Vejjajiva. They have three children -- Dr Alisa Wacharasindhu, head of a paediatric psychiatry unit at Chulalongkorn University's faculty of medicine, Ngamphan Vejjajiva, who won the SEA Write Award in 2006, and Mr Abhisit.