General Somyot Pumpanmuang met with 259 senior Immigration officials at Royal Thai Police headquarters in Bangkok and handed out brochures noting the six main ways in which Immigration officials allegedly take bribes.
The gathering follows the news last week that a key suspect in the bombing at Erawan Shrine in Bangkok was able to bribe his way past Thai Immigration officials in travelling overland at a border crossing from Thailand to Cambodia and was only arrested when the Cambodian officials stopped and arrested him.
While the meeting was closed to the media, reporters did sight copies of the brochure issued to Immigration staff, listing six main methods used to take bribes.
General Somyot, who is being replaced at the end of the month, is reported to have said that Immigration officials at Bangkok's two major airports - Suvarnabhumi and Don Muang - took bribes amounting to at least 1.8 million baht a day.
The bribes encompassed dealing with bombers and Rohingya boatpeople as well, the general allegedly told the Immigration officials from all over Thailand.
The approach by immigration damaged the reputation and the stability of Thailand, the general said.
In a list of key issues, the brochure handed out to officials noted that bribes were taking to convert tourists visas to non-Immigration B visas, and that visas were handed out to visitors seeking student visas at institutions that actually had no schools for as little as 12,000 baht.
Establishing that a visitor qualified for a retirement visa without the necessary 800,000 baht in a bank account usually cost 3000 baht, the brochure said.
Tourists who had exceeded their stay were allowed to gain an extra 15 days for a bribe, the brochure said.
Officers also sent people to a third country for a fee, rather than sending them to their home countries.
Sales of Immigration cards were especially prevalent in travels between Thailand, Laos and Vietnam, the brochure said.
With visas on arrival, passengers could be asked to pay an illegal extra fee of between 300 baht and 500 baht per person, the general said.