Malacañang has debunked claims made by controversial lawyer Larry Gadon that face masks are not effective against COVID-19, saying the losing senatorial candidate is not a doctor.

Gadon went viral on social media for taping his face mask on his face shield instead of wearing it properly.

Instead of apologizing, Gadon said he does not think face masks are effective against COVID-19, or else the country would not have hundreds of thousands of people who tested positive for the disease.

In his Monday press conference, presidential spokesman Harry Roque said Gadon is not a health expert.

"Hindi naman po doktor kasi si Larry Gadon. 'Yan po ay pañero ko (Larry Gadon is not a doctor. We're both lawyers) so let that be his personal opinion," he said.

Roque, however, echoed the claim of health experts that face masks and face shields are very effective against the disease.

"Ang pagsusuot po ng maskara (The wearing of face masks) can reduce the risk of acquiring the disease by as much as 85 percent," he said.

"Sasamahan pa 'yan ng face shield, almost 90+ percent po ang probability na mapo-protect tayo sa COVID (If you also wear a face shield, the probability of you being protected from COVID-19 jumps to 90+ percent)," he added.

The Palace official urged the public to wear their masks especially when outside of their residence.

"Sana po ay 'wag na tayo mag-antay na tayo pa ay magiging susunod na biktima (Let's not wait for the time when we will be the next victim)," Roque said.

"Alam na po natin 'yan sa buong mundo na epektibo po ang pagsusuot ng face mask, paghuhugas ng kamay, at social distancing (We've seen how effective the wearing of face masks, handwashing, and social distancing are against COVID-19)," he added.