The director of Srinakharinwirot University's Educational and Psychological Test Bureau has acknowledged seven criminal charges in an alleged fraud involving recruitment examinations for local government positions.

The admission comes as police widen their investigation into one of the country's largest public recruitment scandals.

Ruangdech Sirikit appeared before Crime Suppression Division investigators on Friday after being summoned as one of 13 suspects ordered to acknowledge charges by that deadline.

Police said Mr Ruangdech was implicated by Win Thanaphatcharaphokin, an adviser to the director of the Office of Promotion and Training at Kasetsart University.

Mr Win allegedly told investigators he coordinated with Mr Ruangdech to obtain examination questions and files before delivering them to a group of 11 people at a house in Nonthaburi, where answer sheets were allegedly altered.

A source said Mr Ruangdech admitted delivering a flash drive to Mr Win, but insisted he acted under employment instructions from former Department of Local Administration director-general Teeruth Supawiboonpol and denied any wrongdoing. He added that he knew Mr Win through their shared involvement in the education sector.

After questioning, Mr Ruangdech was released without bail.

He faces seven charges: malfeasance in office; forging an official document as a public official; certifying false evidence in an official document; jointly removing or causing the loss of another person's documents; jointly forging official documents; jointly opening or taking another person's sealed documents to learn their contents; and jointly importing false information into a computer system.

Mr Teeruth, also among the suspects, postponed his meeting with investigators until next week.

Police said three or four people found at the Nonthaburi house also acknowledged charges yesterday, while several others sought postponements.

They face allegations including criminal conspiracy and violations of the Computer Crime Act.

Deputy Interior Minister Worasit Liangprasit said he had instructed relevant agencies to speed up fact-finding and gather evidence over alleged irregularities in local administrative organisation recruitment exams. He expected progress or conclusions on actionable issues within the next week.