The raid at the Nataree massage parlour continues to rattle authorities as police investigate the purpose of paper chits bearing a picture of a mythological animal found in the possession some of the women arrested there.
An investigation team led by senior inspector-general Termpong Sitthipraset will look into all possible kickbacks, based on clues found there, including blue paper chits, and the supposed ignorance of officers involved, deputy police spokesman Pol Maj Gen Songphol Wattanachai said on Monday.
Mystery surrounds the purpose of the pieces of paper, which bear an image of a Singha, a mythical lion and temple guardian.
"There will be punishment for any police officers found to have committed any wrongdoing," the deputy spokesman said.
Several media outlets reported on Monday that the small paper sheets with the picture of a Singha were found in the possession of foreign masseuses working at the parlour arrested during the raid.
According to the reports, the paper was proof of payment to authorities in exchange for being allowed to work illegally in Thailand. They allegedly each paid 1,000 baht a month in exchange for officials turning a blind eye.
Kritsada Boonratch, permanent secretary for interior affairs, promised decisive action against any officials found involved in the sex trade at the massage palour.
The Huai Khwang police station chief and three other senior officers have been transferred to inactive posts pending investigation since Department of Provincial Administration officials, police and soldiers raided the place on Ratchadaphisek Road in Huai Khwang district on June 7.
They arrested 121 female sex workers, 77 of them foreigners. Several of those arrested were aged under 18.
They also found notebooks recording payments, thought to be bribes, to some tourist police, Bangkok Metropolitan Administration officials and others.
On Friday, 57 foreign sex workers appeared before the Criminal Court as police applied to detain them for investigation on charges of illegally working in the country, while another 20 were sent to the North Bangkok District Court on charges of working in occupations different from those described in their papers.
Police have pressed human trafficking charges against five executives of the palour.