MANILA- "Why did he go there?"

Malacañang on Friday questioned why former Philippine Foreign Affairs Secretary Albert del Rosario had to go to Hong Kong, knowing that he might be held by authorities there just like former Ombudsman Conchita Carpio Morales.

Del Rosario, who led Manila's winning arbitration case against Beijing, said he was stuck at Hong Kong immigration on Friday waiting for clearance.

By Friday afternoon, he was denied entry. He is expected to fly back to Manila later in the day.

• Hong Kong denies entry to Philippines' former top diplomat

"Why did he go there? That's my question to him. Was this deliberate on his part so that he would have the same situation where he could use it as a forum for his advocacy?" Presidential Spokesperson Salvador Panelo said in a phone interview with CNN Philippines.

• Ex-DFA chief and China nemesis Del Rosario held at HK airport

Del Rosario, a non-executive director of Hong Kong's First Pacific, was traveling to the Chinese special administrative region for a shareholders meeting, said his lawyer, Anne Marie Corominas.

Manila's former top diplomat said there was "no rational explanation" as to why he was held by Hong Kong authorities.

"We are of course questioning what the reasons are, why we were detained here or held up," Del Rosario said earlier Friday.

Panelo said he "cannot also understand" why Del Rosario still flew to Hong Kong despite Morales' earlier troubles with immigration officials there.

"Because if I were Del Rosario, I would have not gone to Hong Kong because I would be—I’m sure, I would have anticipated, that I would be going to the same ordeal like the former Ombudsman did. Now why did he go there? That’s my question to him," he said.

Morales, who along with Del Rosario, hauled Chinese President Xi Jinping to the International Criminal Court for alleged crimes against humanity, was also held for questioning at Hong Kong Airport last May.

The former Philippine officials sought an investigation into Beijing's "systematic plan to control the South China Sea."

HONG KONG HAS THE RIGHT TO DO SO

Despite "harassment" cries from Del Rosario's camp, Panelo said Manila could not question Hong Kong's decision to deny entry to foreigners.

"We cannot question the authority, the right of a country to stop or to investigate any guest or visitor who wanted to enter that particular country. That's their exclusive domain," Panelo, also the chief legal counsel of President Rodrigo Duterte, said.

"Now, whether or not a person is a security risk to them is for them to determine, not us, not the country where that person belongs," he said.

Justice Secretary Menardo Guevarra, who is the current caretaker of government while Duterte is in Thailand for the weekend, said Friday he would instruct the Department of Foreign Affairs to look into Del Rosario's case and help.

"As OIC (officer-in-charge), I will request the DFA to find out the reason for former SFA's (secretary of Foreign Affairs) exclusion and extend whatever assistance could be given to him as a former foreign minister of our country," he said.

"But personally, I believe that the lesson derived from former Ombudsman Morales' similar experience should have been clear to him," he said.

Panelo, meanwhile, assured Del Rosario that the Philippine government would help all Filipinos overseas in need of assistance.

"We will help anybody in need of help in other countries. As far as we're concerned, mga kababayan natin yan (they're our fellow countrymen)."

Del Rosario served as foreign affairs chief during the time of former President Benigno Aquino III. He has been critical of the Duterte administration's handling of the country's dispute with China over the South China Sea.