She said the Culture Ministry would co-host the chanting and royal-sponsored cremation, as well as publish and distribute to funeral guests a biography of Seri, whose sudden death is a great loss to Thai traditional theatre.

The National Artist's daughter, Supamongkol Wangnaitham, said Seri had previously suffered from heart disease, asthma and emphysema, prompting occasional hospital stays.

Seri was hospitalised again on Tuesday after suffering from exhaustion following a trip to Rama II Park in Samut Songkhram's Amphawa district. He was able to speak cheerfully with his students who visited him in hospital on Wednesday, she said.

However, Seri felt chest pains at 1am yesterday and received medication, after which he went to sleep, then passed away at 3am, said Supamongkol. He was pronounced dead after 30 minutes of coronary resuscitation failed.

Fine Arts Department director-general Arak Sanghitkul revealed that Seri had written his last piece, a "Ramayana" epic khon play featuring the Maiyarap Battle episode, to be performed in front of HRH Princess Maha Chakri Sirindhorn on February 10 at Rama II Park.

"The country has lost its great master of theatricals," he said, adding that Seri's idea of using comedy acts in the intervals during Thai dramatic-arts performances made them more interesting.

This sudden loss has caused grief and caught many of Seri's students off guard, including khon artists Prasart Thong-aram and Pakorn Pornpisut, both of whom had worked with Seri for more than three decades. He was their mentor.

Seri was born in Bangkok on January 3, 1937 to Khun Sathokthanasan (Leu Wangnaitham) and his wife Sa-nga.

After receiving an advanced education from the Fine Arts Department's College of Dramatic Arts in 1954, Seri served as a musical artist at the department. He was eventually elevated to a Level 8 artist and became head of the department's Music Division.

Seri also received a scholarship to study fine arts at the East-West Centre at the University of Hawaii from 1962-65.

He was honoured as a National Artist for acting (drama) in 1988. A master of the khon - a high art form encapsulating all Thai fine arts - Seri was also an actor, dancer, playwright, director, songwriter, poet and television producer.

Seri produced outstanding performance programmes of Thai fine arts, including the popular "Srisuk Nattakham" - a variety show of Thai performance art and comedy acts that ran for 13 years.

His educational programme "Singkhuanroo Kon Doo Khon" (Things You Need to Know Before Viewing Khon) in 1972 also helped younger generations to understand and become interested in this high art form.

Seri also designed many important cultural events, including a 2,526-strong khon performance in Sanam Luang to celebrate the 200th anniversary of the Rattanakosin area.