MANILA - Davao City Vice Mayor Paolo Duterte and his brother-in-law, Atty. Manases Carpio, attended the resumption of a Senate probe into a P6.4 billion drug shipment into the country.

Before the start of the hearing, Duterte and Carpio stayed at the office of Senate Majority Leader Tito Sotto.

PANOORIN: Davao City Vice Mayor Paolo Duterte, dumating na sa Senado at kasalukuyang nasa tanggapan ng Majority Leader pic.twitter.com/Pb0Hi9ttaJ

— Zandro Ochona (@ZandroDZMM) September 7, 2017

Businessman Mark Taguba, who brokered the 600-kilogram shipment, earlier tagged Duterte and Carpio as members of the alleged "Davao Group," which he allegedly bribed to facilitate corruption at the Bureau of Customs.

Taguba later apologized and said Duterte and Carpio's alleged involvement in the corruption controversy was "hearsay in nature."

The vice mayor and Carpio have both denied the allegations.

• Vice Mayor Duterte downplays 'hearsay' testimony of Customs broker
• 'Desperate rumor': Duterte son-in-law explains Customs visit

Their appearance at the hearing "demonstrates that both gentlemen are willing and ready to face malicious allegations intended to impugn their character and credibility," Presidential Spokesperson Ernie Abella said in a statement.

"The President has said in numerous occasions that he would not interfere and he believes that both gentlemen, Vice Mayor Duterte and Atty Carpio, can hold their own at the Senate," Abella added.

President Duterte earlier said he sees no problem if his son and son-in-law attend the Senate hearing.

“They should,” Duterte said. “He’s old enough to know. He can take care of his problem. I don’t speculate. I don’t give him advice. I just said ‘kung wala ka talagang kasalanan, bakit hindi ka pumunta doon?’”

• Duterte: Paolo can take care of his problem

TRILLANES VOW

Senator Antonio Trillanes IV however promised to present evidence linking President Rodrigo Duterte's son and son-in-law to the narcotics trade during Thursday's hearing.

"Kapag pumunta sila diyan, talagang ibubulaga ko sa kanila yung ebidensya laban sa kanila at magli-link sa kanila sa droga na ito," Trillanes told DZMM.

Trillanes and Senator Richard Gordon had traded barbs over whether to invite the President's relatives to the investigation.

Their heated exchange prompted Gordon to file an ethics complaint against Trillanes, whom he accused of "continuous, unabated, unparliamentary acts, language and conduct."

Watch the live streaming video of the hearing here.