Security analyst and former Magdalo partylist representative Ashley Acedillo does not believe President Duterte's statement that he had an agreement with China regarding the presence of Chinese survey ships in Benham Rise.
Acedillo said that if there was really an agreement, President Duterte should reveal its details.
"Ilabas nyo ang kasunduan. Disclose it and give us the guidelines," said Acedillo in an interview with radio DZMM.
Duterte on Tuesday downplayed China's admission that Chinese ships sailed in Benham Rise, which the Philippines has sovereign rights.
China, meanwhile, praised Duterte for his handling of the issue.
Acedillo said Duterte's agreement with Beijing needs to be disclosed in full, as this will form the basis of a code of conduct for Philippine coastguard and Navy personnel who will patrol Benham Rise.
He added that if Chinese ships surveyed Benham Rise with Duterte's blessings, then the Philippines should also be given the survey's findings.
"At the very least we are entitled to get the information and data which became the result of those surveys. Reciprocal yan dapat," Acedillo continued.
He doubted China's claims that its ships sailed through Benham Rise under "right of innocent passage" and "freedom of navigation."
"Hindi ganoon kadali at hindi ganun kainosente ang ginawa nila sa Benham Rise," Acedillo said. He explained that the information he got was that the Chinese ships lingered for a long time in Philippine waters instead of simply sailing through Benham Rise.
He also echoed Defense Secretary Delfin Lorenzana's concern that China may have been surveying the area to look for areas where it can hide submarines.
Supreme Court Justice Antonio Carpio on Tuesday said that China was not doing anything illegal under international law if it was searching Benham Rise for an area where it can park submarines.
But Acedillo insisted that Chinese submarines should not be allowed in the area.
"These submarines pose a national security threat to our surface vessels na hindi nakakakita ng submarino," said Acedillo.
China has said that it is not questioning the Philippines' rights to Benham Rise, but insisted that it was doing nothing illegal under international law.