Ampon Tangnoppakul, alias Ah Kong, alias Uncle SMS, was pronounced dead on Tuesday morning after passing away in a Bangkok prison hospital where he was being treated for acute stomachache. He was 61.
Mr Ampon was sentenced to 20 years in jail after the Criminal Court on Nov 24 last year found him guilty of lese majeste and computer crimes.
He was found guilty on four counts under two laws - Article 112 of the Criminal Code, or the lese majeste law, and Article 14 of the Computer Crimes Act. He was sentenced to five years in prison on each count. The sentences to be cumulative.