Philippine President Rodrigo Duterte's son Paolo has told a senate inquiry that he has no link to a seized shipment of $A156 million ($US125 million) worth of narcotics from China, dismissing as "baseless" the allegations of his involvement in the drugs trade.
Opponents of the president, who has instigated a fierce crackdown on a trade he says is destroying the country, say they believe his son Paolo might have helped ease the entry of the drug shipment at the port in Manila.
Duterte said on Tuesday he had told Paolo to attend the senate investigation if he had nothing to hide, besides advising him not to answer questions and invoke his right to keep silent.
"I cannot answer allegations based on hearsay," Paolo Duterte, the deputy mayor of the southern city of Davao, told the Senate.
"My presence here is for the Filipino people and for my fellow Davaoenos whom I serve," he added, referring to the people of Davao, where his father served as mayor for more than two decades before being elected president in 2016.
The Philippine leader has repeatedly said he would resign if critics could prove any members of his family were involved in corruption.
Senator Antonio Trillanes, a staunch critic of the president, displayed to the Senate panel photographs of Paolo Duterte beside a businessman who was behind the shipment in which the alleged drugs were found.
The president's son-in-law, Manases Carpio, who has also been accused of links to the May drug shipment from China, told the hearing he had no involvement.