It may have been a "case" of self-quarantine gone wrong.

UPDATE
Four Chinese arrested for allegedly killing compatriot in Kamphaeng Phet
National
Feb 29. 2020

By THE NATION
Four Chinese nationals were arrested for allegedly killing a Chinese businessman, stuffing the body in a suitcase and dumping it in the Ping River in Kamphaeng Phet province, Pol General Krisana Pattanacharoen, deputy spokesman of the Royal Thai Police, said on Saturday (February 29).

“The body of Wang Jun, aged 30, was found doubled over in a black suitcase floating in Ping River on Tuesday this week with the ankles tied with plastic cables.” he said. “Police divers are still searching for Zhu Bing, 28, his wife, who has been missing and they believe might have been murdered in the same fashion.”

Jun arrived on February 12 with a group of Chinese nationals who visited Pattaya and left the country on February 14 while he stayed on.

“Officials from Kamphaeng Phet Station have tracked down four suspects connected to the murder, all Chinese nationals,” added Krisana. “Preliminarily they have been charged with three offences: first-degree murder, kidnapping and detaining others against their will and resulting in death, and moving or destroying a dead body with an intention to cover the cause of death. These offences carry a prison sentence of 20 years, with maximum punishment being execution.”
https://www.nationthailand.com/news/303 ... l_referral