The Bureau of Immigration should intensify its investigation and provide evidence on the allegations that some Chinese nationals were acting as sleeper cells in the Philippines, Senator Francis Escudero said on Thursday.

Reports of espionage were raised over the influx of Chinese students in the country amid Beijing’s heightened aggression in the West Philippine Sea.

Escudero said the mounting concerns over the presence of Chinese students in the Cagayan region should push the BI to conduct a deeper probe on the “allegations that some of them may be acting as spies.”

Until proven otherwise, Escudero emphasized that the accusations against these Chinese nationals “remain baseless, unfair, and should not cause undue alarm” even in light of the ongoing territorial dispute between Manila and Beijing over the WPS.

“For now, we have nothing to worry about unless there’s enough evidence projected,” Escudero said in Filipino during a television interview.

The senator slammed the BI, noting that the agency should be questioned for allowing a “growing number of Chinese students” in the country.

“If there is really doubt that they are spies, why didn't the Bureau of Immigration do their job?,” he asked

Escudero said the BI should be summoned first as the Senate called for an inquiry over the influx of Chinese students in the country.

He noted that only the BI could shed light on the matter and ascertain whether any lapses have occurred in fulfilling their responsibilities.

Senator Win Gatchalian on Thursday filed a resolution seeking an inquiry on foreign students' alleged payment of up to P2 million to get degrees in various private institutions in Cagayan.

The security concerns over the Chinese students’ influx in the area came after Dr. Chester Cabalza, a University of the Philippines professor and founding president of the think tank International Development and Security Cooperation, reported their alleged payments to get college degrees.

Gatchalian urged the Commission on Higher Education (CHED) to investigate Cabalza’s report.

The CHED said it would investigate the concern after Cabalza formalizes his complaint, with the necessary evidence so that it could follow due process.

The commission earlier tagged Cabalza’s remarks as serious allegations.