According to AFP, Mr. Thaksin (75 years old) faces a sentence of up to 15 years in prison if convicted of violating the law when the military - the law strictly protects the Thai Royal Family from all forms of insult or criticism.
The case involves Mr. Thaksin's statements in an interview with the Korean media about a decade ago. The verdict is expected to be announced in the next few weeks.
Thaksin's lawyer - Mr. Winyat Chatmontri - said that the customer had started giving statements since morning and would continue throughout the day. About 50 supporters wearing red shirts with Mr. Thaksin's image gathered outside the court to express their support.
A figure who has had a great influence in Thai politics for more than two decades, Mr. Thaksin served two terms as prime minister before being overthrown in the 2006 military coup. He lived in exiledity for 15 years and returned to Thailand in August 2023 - the day the Pheu Thai Party supported by his family returned to power.
As soon as he returned home, he was sentenced to 8 years in prison for corruption and abuse of power allegations, which was later pardoned by King Maha Vajiralongkorn, reduced to 1 year. In recent interviews, Mr. Thaksin expressed his loyalty to the royal family and thanked them for their pardon.
The trial comes as the Shinawatra family faces major political challenges. On July 1, Mr. Thaksin's daughter - incumbent Prime Minister Paetongtarn Shinawatra - was suspended from office by the Constitutional Court to serve a moral investigation related to a leaked diplomatic phone call with Cambodian Senate President Hun Sen.
This controversial call has caused the ruling coalition led by the Pheu Thai party to lose support from conservative parties, forcing the current government to operate with a fragile majority under an interim prime minister.