Metro Manila (CNN Philippines) — The Philippine National Police (PNP) on Monday said personnel from the National Bureau of Investigation (NBI) and Bureau of Immigration (BI) may be involved in the kidnapping of Korean nationals in Angeles City.

On Saturday, the PNP Anti-kidnapping Group (PNP-AKG) arrested three Koreans and a Filipino for kidnapping four Koreans. The arrested suspects revealed they were in cahoots with the NBI and the BI who created operational plans targeting Korean victims.

"Sila ang nagplano ng kidnapping at ginamit nila, kumonek sila sa rogue members ng Bureau of Immigration at National Bureau of Investigation. Meron sila na kasama na rogue members ng BI at NBI sa kidnapping na ito in the pretext na meron siyang violation sa immigration rules," PNP Chief Director General Ronald "Bato" Dela Rosa in a press briefing.

[Translation: They planned the kidnapping and used rogue members of the Bureau of Immigration and the National Bureau of Investigation. They were with rogue members of the BI and NBI in the kidnapping in the pretext of them violating immigration rules.]

He said policemen are looking for at least four NBI agents and two immigration personnel, and that they are now coordinating with the two agencies to verify and identify the personnel involved.

Lee Jung Dae, one of four kidnapped Korean nationals, was rescued on Saturday at the BI parking lot in Intramuros, Manila.

PNP-AKG Chief Glenn Dumlao said Lee and three others were abducted on November 24 in Angeles City, Pampanga.

Dumlao said Korean nationals Cha Jae Youn, Cha Dae Sun, Kim Min Kwan alias Mike Lim, and Filipino Raymond Flores are the suspects, who initially demanded P1.2 million as ransom.

Three of the four kidnap victims were released after the ransom was paid >>when?<<, but the suspects demanded another P4 million for the release of the the last victim, Lee Jung Dae.

Flores, one of the suspects, denied involvement in the kidnapping.

He said he was just the driver of Mike Lim, his cousin's husband, and did not understand what was happening during the negotiations because they were speaking in Korean.

Lim verified Flores' statement, saying Flores was innocent. When asked if he was involved, Lim said, "Yes. I (was) involved."

Dela Rosa said the incident was similiar to the case of Jee Ick Joo, a Korean businessman who was kidnapped and killed by police officers inside their headquarters in Camp Crame in Quezon City in January.

"Kasi, later pagnakuha ang pera, since kilala nila ang victim nitong mga Koreanong mga suspects e, papatayin din nila ito. Kasi kilala sila. Pati immigration agents at NBI agents na involved dito," the PNP chief added.

[Translation: Once they get the money, because the victims know the suspects, they will be killed. Even the Immigration agents and the NBI agents involved.]

The Department of Justice filed criminal charges against at two policemen and a number of "John Does" for the killing.

The police accused the Korean national of being involved in the drug trade.

His death prompted President Rodrigo Duterte to order the Philippine Drug Enforcement Agency take over the drug war from the police.

RELATED: Dela Rosa expresses shame over killing of Korean in Camp Crame