MANILA - The International Criminal Court is studying whether or not it has jurisdiction over a communication filed against Chinese President Xi Jinping by former Philippine officials, a lawyer from their camp said Thursday.

The ICC Office of the Prosecutor, in a email, said it was "analyzing the allegations identified in your communication with the assistance of other related communications and other information available," lawyer Anne Marie Corominas said in an interview with CNN Philippines.

"The purpose of the analysis is to see if the alleged crimes are within the jurisdiction," added Corominas, who delivered the complaint to the Hague-based court.

"If they do, that would open a preliminary investigation," she added.

However, the ICC Office of the Prosecutor informed their camp that a "meaningful analysis... can take some time."

The e-mail from the office, she said, was dated May 20, the eve of Morales' detention in Hong Kong.

Xi and other Chinese officials allegedly committed crimes against humanity in implementing Beijing's "systematic plan to control the South China Sea," Filipino fishermen, former Foreign Affairs Secretary Albert del Rosario and former Ombudsman Conchita Carpio Morales said in their complaint.

Morales flew to Hong Kong with her children and grandchildren for a family vacation but was barred from entering the special administrative region of China.

Authorities did not explain why she was banned, even as the Philippine consulate communicated with Hong Kong officials.

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It was during Del Rosario's time as top Philippine diplomat that the country brought China before a UN-backed arbitral tribunal in 2013 for incursions in the country's exclusive economic zone within the disputed South China Sea.

The tribunal, based in The Hague, invalidated China's 9-dash line claim over the waters and recognized traditional fishing rights of Filipinos in the Scarborough Shoal, an area where Beijing's patrol ships had shooed away Philippine fishermen.

The Philippines and China have long sparred over the South China Sea, but relations improved considerably under President Rodrigo Duterte, who set aside the 2016 landmark legal victory for enhanced ties.

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Manila quit the world's only permanent war crimes tribunal after the ICC launched in 2018 a preliminary examination of Duterte's drug crackdown that has killed thousands and drawn international censure.

The Philippine defection from the court took effect last March 17.

ICC Prosecutor Fatou Bensouda the following day said her examination into the allegations against Duterte would continue.

The ICC, however, is unlikely to investigate Xi given Manila's departure from the court, and the complaint's citing of crimes against the environment instead of crimes against humanity, said David Bosco, an associate professor at Indiana University's School of Global and International Studies.

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The complaint may also be "a futile exercise" because the ICC "has no jurisdiction over China," Duterte's spokesperson Salvador Panelo was quoted as saying on Saturday.

With a report from Agence France-Presse