Police chief Somyot Pumpanmuang has confirmed the arrest of a person suspected of posting malicious rumours on social media that Prime Minister Prayut Chan-o-cha and his wife had transferred more than 10 billion baht to Singapore.
Gen Somyot said on Thursday that authorities had arrested the suspect but declined to give details, saying the interrogation was still under way.
Whether the suspect belonged to an anti-government group was likely to be known after questioning had been completed, he said.
Gen Somyot warned people against posting or forwarding messages which might cause damage to others. This was a violation of the Computer Crimes Act, he said.
He said he favoured the acquisition of a single gateway system, which would make it easier to track down these offenders.
Prawut Thawornsiri, the police spokesman, said the suspect is a woman and had been detained by the military under martial law.
The military was now in the process of obtaining an arrest warrant before handing the woman over to the police.
Pol Lt Gen Prawut said initial inquiries indicated she had a connection with those who previously posted fabricated stories of a fresh coup on social media, and several other damaging reports. They were believed to have acted on the orders of the same person.
"The woman is being detained by the military. Police have joined in the investigation," he said.
Pol Gen Prawut said he expected there would be more information on the matter at a press conference at the Royal Thai Police Office on Friday.