Since Pol Gen Chatchawal Suksomjit was appointed permanent secretary for justice, all eyes have turned to the now-vacant seat of the Department of Special Investigation (DSI) chief.
The cabinet on Wednesday approved the transfers of several state officials following a number of retirements on Tuesday.
Pol Gen Chatchawal replaced Kittipong Kittiyarak, who is now an adviser to Prime Minister Prayut Chan-o-cha.
Previously, Charnchao Chaiyanukit, deputy permanent secretary for justice was tipped for promotion, with sources saying he had the support of Justice Minister Paiboon Koomchaya.
Pol Gen Chatchawal had promised the government that Pol Gen Somyot Pumpanmuang would become national police chief, even when Pol Gen Somyot was less senior than Pol Gen Chatchawal.
Pol Gen Chatchawal is now the first policeman to become permanent secretary for justice.
Pol Lt Gen Amnuay Nimmano has emerged as a frontrunner for the DSI hot seat. He was recently appointed commander of Provincial Police Region 1 and was formerly a deputy Bangkok police chief.
Pol Lt Gen Amnuay had his sights set on the DSI chief seat, but he was made Provincial Police Region 1 chief so that he would be elevated from a police major-general to police lieutenant-general first, according to a source.
This way, if appointed as DSI chief, Pol Lt Gen Amnuay would be likely to revive the case concerning crackdowns on red-shirt protesters in 2010, the source said.
Prosecutors filed the case with the Criminal Court seeking to indict former prime minister Abhisit Vejjajiva and his former deputy Suthep Thaugsuban following a DSI recommendation.
Mr Abhisit and Mr Suthep were charged with murder and attempted murder in connection with the 2010 crackdowns.
But on Aug 28, the Criminal Court dismissed the case against the pair, saying it did not have the authority to try the case and jurisdiction rested with the Supreme Court's Criminal Division for Holders of Political Positions.
Pol Lt Gen Amnuay once served as a member of a committee under the Centre for the Resolution of the Emergency Situation, set up by Mr Abhisit's Democrat government to deal with red-shirt protesters at the time.
If the case is revived, the focus of the investigation could target the men in black who allegedly fought with red shirts against authorities. This could implicate some key figures of the red-shirt movement.
Pol Lt Gen Amnuay led several police operations to recover weapons allegedly in the hands of red-shirt protesters and held several press conferences announcing seizures.
Speaking after chairing a meeting of Justice Ministry officials on Thursday, Gen Paiboon said that no one has yet been approached to take the job of DSI chief, adding that the post is open to outsiders.
Khunying Porntip Rojanasunan, director of the Central Institute of Forensic Science, yesterday wrote on her Facebook page that Pol Gen Chatchawal's new appointment showed that the government only favoured those who have affiliations with it or lobby it.