Christopher "Bong" Go, President Rodrigo Duterte's right-hand man, vowed on Monday to step down from his post if proven he had intervened in the procurement of 2 new Navy ships.

"Kung mayroon ba akong tinawagan, tinanong o nag-influence man lang ba ako para ibaligtad -- 'pag may nakapagturo, paglabas ko rito I will resign," the special assistant to the President told senators investigating the frigate deal.

(If I called anybody, asked them or exerted influence over the deal -- if any one can point to me, I will resign.)

He also branded as "fake news" the media reports that he supposedly endorsed a Korean firm to provide the the combat management systems for missile-capable ships.

• Duterte long-time aide denies meddling in frigate deal