Two of the 15 robbers were arrested and face several charges, including kidnapping, police said.
One of the arrested men, Larry Ferrer, 29, was an informant of the National Bureau of Investigation, police said. The other suspect, Oscar Lakbay, 41, claimed to be an NBI agent, but police said the claim was false.
NBI spokesman Ric Diaz said Ferrer will be investigated.
The seven victims were leaving the Pagsanjan Rapids Hotel in Pagsanjan town, about 65 kilometers southeast of Manila, when three men took them at gunpoint in the hotel parking lot, police said.
The men shoved the foreigners inside the rented van of Australian Yun Hui Lee while the two Filipinos were forced into another vehicle.
The group fled toward Calamba town and met up with 12 accomplices on the way, police said.
The robbers stopped in a restaurant parking lot and forced the victims to hand over P200,000 and several cellular phones. They were released three hours after they were abducted.
The freed foreigners were traveling in a rented van but were still being followed by two robbers when police caught up with them.
Besides Yun, the victims were his son Eun Seuk Lee, New Zealanders Bayden Majgakahia, Fred Nathan and Brett Moshiemn, and two Filipino companions.
The other robbers fled with the money, but the phones were recovered, police said.
Police said the men also face charges of kidnapping, illegal possession of firearms and robbery. — Rene Alviar