The police chief has transferred the commissioner of the Crime Suppression Division (CSD) to an inactive post.
Pol Gen Chakthip Chaijinda signed the order on Friday to move Akradej Pimolsri to the Royal Thai Police Operations Center and to transfer Pol Maj Gen Charn Wimolsri, deputy commissioner of the Central Investigation Bureau, to be acting CSD chief.
Pol Maj Gen Akradej had been promoted to head the CSD, the Thai answer to the US Federal Bureau of Investigation, in late June.
The move was sudden as Pol Maj Gen Akradej led a news conference on a case earlier on Friday.
Police spokesman Gen Dejnarong Suthicharnbuncha told Thai media on Saturday the police chief wanted Pol Maj Gen Akradej, a competent investigator, to handle special cases assigned by him.
But it was speculated the transfer might have been part of Pol Gen Chakthip's plan to put more of his men in key positions for better control of the 220,000-strong police force after he took the position in October.