The Centre for National Anti-Corruption (CNAC) says no irregularities were found in the casting of the statues of the seven former Thai kings at Rajabhakti Park in Prachuap Khiri Khan.
This was underlined in a CNAC press briefing Wednesday, chaired by Justice Minister Paiboon Koomchaya.
The National Anti-Corruption Centre was formed by the military regime after the May 22, 2014, coup. It answers directly to Prime Minister Prayut Chan-o-cha, who chaired its first meeting on Jan 14 of last year.
The briefing was attended by Auditor-General Pisit Leelavachiropas, Office of the Public Sector Anti-Corruption Commission (PACC) secretary-general Prayong Preeyajit and National Anti-Corruption Commission deputy secretary-general Yongyut Malithong.
Gen Paiboon said a petition was sent to him to look into irregularities involving kickbacks in the project so he asked the agencies concerned to help investigate.
The case centred on an amulet trader who allegedly demanded kickbacks from foundries hired to cast the statues of the kings at the park.
Former army chief Gen Udomdej Sitabutr earlier said that the amulet dealer had attempted to demand commission fees from the foundries, but the army had taken the money back from him.
Mr Prayong said Wednesday that the PACC was in charge of investigating the kickbacks in particular.
He said the money had been paid between private parities but it was regarded as a business-based reward as the amulet trader brought work to the foundries.
He said 6-7% of the hired payment is set aside for that purpose.
The hired payment was still in line with market prices and nothing suspicious was detected based on questioning and documentary evidence, Mr Prayong said.
Mr Pisit echoed the comments of the PACC chief.
Based on the accounts of the five foundries and their financial records, Mr Pisit said they paid money to the amulet trader for what they called "charges for recommending jobs".
The issue stemmed from the the foundries' own management.
Mr Pisit said the Office of the Auditor-General also looked into the background of the amulet trader, called Sian U, to find out whether he had sufficient expertise to give advice to the foundries in relation to the casting of the statues.
It was found that Sian U has his own foundry, Siam Pura Co, and he has previous experience having cast a large statue of Luang Pu Tuad.
Sian U obtained 20 million baht for his advisory role and he had the right to receive this sum because he helped tackle various obstacles when the statues were being cast, Mr Pisit said.
The cost of each statue was also reduced from 70 million baht each to 40-45 million baht.
However, Sian U was later told by the army not to take that money so he donated the sum back to the Rajabhakti Park project's fund through five cheques under the name of Siam Pura Co, Mr Pisit said.
After the money was returned, the army issued him receipts.
According to Mr Pisit, nothing untoward was detected in the process of obtaining the donations for the project.
As of Dec 31 last year, about 733 million baht, including interest payments, had been credited to the account.
About 140 million baht is currently still in the account.