Suvarnabhumi airport will undergo a security overhaul after the escape of a German convict from the airport earlier this month.
The airport's director, Rawewan Netrakavesna, said officials have inspected the more than 300 fire exits at the airport for defects.
Additional security measures are being considered, she said.
Carlo Konstantin Kohl, 25, was being extradited from Australia to Germany when he managed to slip his security escort during a stopover in Bangkok on May 15. He exited Suvarnabhumi airport undetected while the two private security guards allegedly slept.
Kohl was found guilty of several robberies in Australia and completed a prison term there. He was being escorted to Germany to face further charges.
An investigation by airport officials found Kohl cut the electricity supplying a fire-exit alarm before fleeing the airport.
An airport source said authorities are investigating whether someone assisted the convict's escape.
Security camera footage showed that Kohl appeared calm during his escape, the source said. He was seen wandering around the airport and stopped for a foot massage on his way out. "It looked like he was waiting for someone to do something," the source said.
The source said the airport could add a second layer of security to prevent a repeat of the escape. That way, if the first layer _ such as the electronic alarm system _ is destroyed, a second layer would still remain operational.
Another airport source said poor staff discipline also posed security risks.
Some airport staff open emergency exit doors and leave them propped open when they go outside for a cigarette, the source said.
Immigration Bureau commissioner Panu Keudlappol said Kohl had served in the German military and was an engineering expert. Police believe he has not travelled far as he had little money.
Immigration police have alerted officers nationwide, particularly in tourist destinations such as Pattaya and Phuket, Pol Lt Gen Panu said.
Pol Col Chartchai Iamsaeng, deputy chief of the Immigration Bureau's investigation unit, said Kohl recently contacted the German embassy in Bangkok asking it to issue him a new passport.
He claimed his old passport was lost, but failed to show up for an appointment to issue a replacement.
Immigration Bureau Division 2 chief Pol Maj Gen Suwichpol Imjairach said the Australian embassy had apologised to Thai police for the mishap.