Department of Foreign Affairs spokesman Raul Hernandez said they summoned Cambodian envoy Hos Sereythonh over remarks in a letter sent to the Philippine Star newspaper, a report by GMA News online said.
Officials want Sereythonh to explain his statement blaming the Philippines and Vietnam for the failure of the Association of Southeast Asian Nations to issue a communique at the end of its meeting in Phnom Penh last month, the GMA News report said.
Hernandez said the DFA want to ask the envoy what he meant when he said the "inflexible and non-negotiable position of two countries of ASEAN is dirty politics."
"We want to know where the ambassador obtained the information on the events as narrated in his letter since these are not consistent with the records of the ASEAN meetings," Hernandez told a news briefing.
Hernandez said it was too early to say if there was a possibility that the Cambodian envoy could be declared persona non grata for his remarks.
"We're not going there yet," Hernandez said.
The ASEAN meeting ended with no final communique after an insistence by the Philippines and Viet Nam that a statement be included concerning disputes with China over ownership of the Scarborough Shoal in the South China Sea.
It was the first time no final official communique was issued in ASEAN's 45-year history.
China isn't one of ASEAN's members, which are Viet Nam, Philippines, Malaysia, Cambodia, Thailand, Brunei, Laos, Singapore, Indonesia and Myanmar.
The Cambodian ambassador's comments in the Philippine Star newspaper is part of continuing finger-pointing by Manila and Phnom Penh over who is to blame for the lack of a final communique.
"The chair (Cambodia) has consistently opposed any mention of the Scarborough Shoal in the joint communique and announced that a joint communique can't be issued," Philippines Foreign Affairs Secretary Albert del Rosario said after attending the ASEAN forum.
But Cambodian Foreign Minister Hor Namhong said all ASEAN members were responsible for the failure to issue a final joint statement, a report by the BBC said at the time.
"I requested that we issue the joint communique without mention of the South China Sea dispute ... but some member countries repeatedly insisted to put the issue of the Scarborough Shoal," Hor said.
"I have told my colleagues that the meeting of the ASEAN foreign ministers is not a court, a place to give a verdict about the dispute," Hor said.
Manila now has Sereythonh in its sights for his article in The Philippine Star.
Sereythonh wrote that insistence by the Philippines and Viet Nam was an attempt to "sabotage and hijack the joint communique" at the ASEAN meeting.
"The souring of the mood which led to the non-issuance of the JC could undoubtedly be attributed to the inflexible and non-negotiable position of the two countries," Sereythonh wrote.
"The two countries demanded that ASEAN collectively must yield to the national interests of the Philippines and Vietnam, even if it is at the expense of ASEAN."
Scarborough Shoal is more than 400 miles off the Chinese coast but 150 miles off the coast of Zambales, a province on the western shore of Luzon Island, the largest and most northern Philippines island.
China is claiming many islands, shoals and rocky outcrops in the South China Sea, among them the Paracel Islands and the Spratly Islands.
As well as Vietnam and China, ownership of various Spratly islands and reefs -- some only visible at low tide -- are disputed by Brunei, Taiwan, Malaysia and the Philippines, although Brunei doesn't occupy any of the islands.
The Spratly dispute has erupted into open military confrontation on occasions, such as the brief 1988 Johnson South Reef skirmish between China and Vietnam in which about 70 Vietnamese military personnel were killed.
At stake are suspected large reserves of oil and natural gas on the seabed that would fall to the winner of a territorial ownership settlement, should one be forthcoming.
China and the Philippines have faced off over fishing rights and in April over Chinese fishing vessels sheltering in poor weather in Scarborough Shoal.
The war of words is set to intensify with the Philippine government announcement this week that it will auction off three areas in the South China Sea for oil and gas exploration -- areas also claimed by China.
Several local and foreign companies are qualified to bid, including French energy giant Total, U.S. company Exxon and Royal Dutch Shell, the BBC reported.