Wannapong Kocharak, deputy director-general of the Department of Special Investigation, has been transferred to the same post at the Central Institute of Forensic Science in a move believed to be related to slow investigation of 2010 political violence in which 89 people were killed.
Under the order signed by Suwana Suwanjutha, the permanent secretary for justice, the transfer to CIFS deputy director adheres to Justice Minister Paiboon Koomchaya's directive to improve coordination between the CIFS and the Royal Thai Police.
However, informed sources at the ministry said the transfer might be related to his investigation of 2010's violent red-shirt protests.
The sources said the investigation initially made little progress, leading to the replacement of the first team of investigators. The staffing change led to the discovery of important pieces of evidence and the investigation now is nearly complete.
A particular snag in the investigation concerned the existence of the so-called "men in black."
Tarit Pengdith, DSI chief during the Democrat-led government of Abhisit Vejjajiva, at first said there were "men in black" among the protesters. Mr Tarit later reversed his statement and described them as "unidentified armed elements."
An initial investigation report referenced evidence indicating the spot from which the black-clad men fired the M79 grenade that killed Gen Romklao Thuwatham during a clash at the Khok Wua intersection on April 10, 2010. But that evidence was never included in the investigation into the 89 deaths, said the sources.
Moreover, in an investigation carried out under Pol Lt Col Wannapong's supervision into alleged share manipulations by a group led by Chai Bunnag, the DSI did not seek indictments in 14 cases.
However, following complaints, the investigation was reopened and misdeeds were found. A number of people subsequently were summonsed to be charged, said the sources.