The National Bureau of Investigation is probing the use of fake exit stamps at airports to facilitate the departure of trafficked individuals, Justice Secretary Jesus Crispin Remulla said Thursday.

"We're already investigating that. We're asking the NBI to investigate it," Remulla said during an ambush interview, referring to the modus operandi to bypass immigration officers.

During a Senate hearing on Tuesday, an alleged human trafficking victim revealed that someone at the airport facilitated his departure using fake exit stamps to bypass the BI.

Alias "Paolo" told senators he was recruited as a customer service representative in Thailand, but he discovered he would be made to work as a scammer in Myanmar.

"We're making that as the starting point of the investigation because the hearings were very revealing as to the modus operandi," Remulla said.

The possible involvement of airport personnel is not being dismissed by the Manila International Airport Authority, MIAA senior assistant general manager Bryan Co said.

Co was responding to a senator's comment that the MIAA should be investigated as the agency which issued the ID passes provided to the trafficking victims.

"While we're not ruling that out, of course, we're undertaking all of the investigation and intelligence buildup so that we can resolve these problems that we face," Co said.

Immigration spokesperson Dana Sandoval said they have yet to find links tying BI personnel to the modus operandi, but that they are open to being investigated.

"We are worried about the matter. We are watching closely the immigration area because it's our jurisdiction," Sandoval said, adding other areas of the airport not within their jurisdiction should also be watched.

The BI recently accosted four persons who tried to leave the country by passing through the employees' entrance at Ninoy Aquino International Airport wearing fake airport ID and passes.

"We want to know how big is the scale of the operation as it is worrisome since they are using the ingress and egrees points of the airports to slip inside the victims to illegally work abroad," Sandoval said.