A state official has been detained for spreading false information that the army is planning a coup to oust the Prayut Chan-o-cha government, the police said on Sunday.
Deputy police spokesman Pol Col Kissana Phathanacharoen said an official was taken in for questioning by police in Chachoengsao, adding he admitted to having forwarded the false information online.
Pol Col Kissana said the police were acting on a request by the army to prosecute those behind the fake news.
On Friday, army chief Gen Narongphan Jitkaewtae assigned Maj Gen Burin Thongprapai, director of the army's Office of the Judge Advocate, to lodge a request for action with the Cyber Crime Investigation Bureau (CCIB).
Pol Col Kissana said the fake news had caused public confusion and harmed the army's reputation.
Though the official, whose identity has not been disclosed, was quizzed by police and admitted to spreading fake news, he has not yet been charged.
Sources say he is likely to face multiple charges including defamation as the case develops further.
Other charges, such as violation of the Emergency Decree and the Computer Crimes Act, may be pursued against him when investigators have enough evidence.
Two to three other people who shared the fake news will also be sought for prosecution, Pol Col Kissana said.
CCIB commissioner Pol Lt Gen Kornchai Klayklueng said the official told police he received the fake news from someone he trusted.
He mistakenly thought it was genuine and rushed to spread the information online, he said.