A former Philippines foreign minister who was denied entry into Hong Kong said Saturday he was barred over his criticisms of China, calling the move "sheer intimidation" by Beijing.
Hong Kong, which has been rocked by massive anti-Beijing protests in recent weeks, on Friday turned away Albert del Rosario, who has spearheaded legal moves against the Chinese government's bullish behaviour in the disputed South China Sea.
Del Rosario, who served as foreign secretary from 2011 to 2016, tried to enter on a diplomatic passport before being held for six hours and put on a flight back to the Philippines.
His lawyer said authorities gave no reason for denying him entry, but del Rosario said he was targeted by Beijing.
"This was sheer intimidation, harassment and retaliation for the positions I've taken against China," he told Manila radio station DZBB on Saturday.
Del Rosario was behind a 2013 case at an international tribunal that ruled against Beijing's claim in the South China Sea.
In March he filed a complaint at the International Criminal Court against Chinese leader Xi Jinping, alleging "crimes against humanity" over the supposed environmental fallout of Beijing's activities in the disputed waters.
He had travelled to Hong Kong for a business meeting, carrying a diplomatic passport that he presented at immigration.
According to Philippines law, former foreign ministers and lower-level officials are allowed to carry diplomatic passports in order to bypass lines, but they do not offer legal protections abroad.
"That's a big help to me because I didn't have to line up in long queues," del Rosario said.
"I fully understood that I did not have immunity."
Officials at the airport told him he was being turned away because of an "immigration reason" but did not provide further details.
Earlier a Philippines government spokesperson said there "might have been a problem with the use" of the passport.
"If you use a diplomatic passport it has to be an official engagement between the Philippines government and the country that you're entering," Martin Andanar told reporters Saturday on the sidelines of a Southeast Asia leaders summit in Bangkok.
Andanar would not be drawn on whether del Rosario was barred from Hong Kong for political reasons, saying only "it's the right of any country to deny anyone".
On Saturday the Philippines foreign ministry said it was revoking all diplomatic passports held by former foreign ministers and ambassadors.
Hong Kong immigration has refused to comment on the case.
The territory was handed over from Britain to China in 1997, though is still run independently under a "one country, two systems" arrangement.
But activists say Beijing has tightened its grip on the financial hub, which has increasingly turned away China critics on arrival at the airport.
Philippines president Rodrigo Duterte has largely backed away from Manila's once-tense standoff with Beijing over its sweeping claims in the resource-rich South China Sea.