Princess Norodom Vacheahra, half-sister of the late King Father Norodom Sihanouk, passed away in Paris on Sunday night at the age of 68, royal officials said.
The body of the princess will be repatriated from France to Cambodia for a funeral.
Prince Sisowath Thomico said she had been in France receiving medical treatment for lung cancer since 2008.
The fifth committee president of the second National Assembly in 1998 and a lawmaker in 2003, the princess was fluent in four languages and obtained a graduate diploma in modern literature from the University of Toulouse in 1966. The princess also graduated from the Institute of Political Sciences.
A royal dancer, the late princess founded the humanitarian association Cambodge 2000 and the Association of Khmer Classical Ballet.
“Her death is a great loss to human resources in Cambodia. In the name of the royal family, I feel deep regret and sadness for the sad news,” Prince Thomico said.