MANILA, Sept. 7 (Xinhua) -- The son and son-in-law of Philippine President Rodrigo Duterte denied on Thursday any involvement in the drug smuggling.

Duterte's eldest son Davao City Vice Mayor Paolo Duterte and son-in-law Manases Carpio, husband of Duterte's daughter Davao City Mayor Sara Duterte, appeared at the Philippine Senate Blue Ribbon Committee to clear their name.

Both have been "name-dropped" by a "broker" in the Bureau of Customs in the ongoing probe on the smuggling of shabu,' a slang term for illicit drug methamphetamine.

The broker has testified in a legislative investigation into how 604 kg of "shabu" worth 6.4 billion pesos (125.4 million U.S. dollars) made it past the customs bureau. The drug shipment was seized last May by customs officials at a warehouse in Valenzuela City.

Duterte's son told the senate that the allegations linking them are "baseless" and based on rumors.

"Once and for all, I have the time to deny any and all baseless allegations thrown against me," Duterte told the senate committee. He refused to answer further questions. "I am sorry but I cannot answer allegations based on hearsay."

For his part, Carpio lamented that he and his brother -in-law "have been publicly crucified based on rumors," Carpio, a lawyer, said his law practice involves representing clients in courts including the Bureau of Customs.

"I am here before this committee to formally dealer that I have no knowledge or involvement in illegal drug shipments...to assist the committee in whatever way I can as a resource person," Carpio said.

President Duterte, who earlier defended his son and son-in-law and called the accusations "malicious," advised the two to appear before the senate committee.

Duterte's spokesman Ernesto Abella said in a statement that the appearance of Duterte's son and Carpio before the senate committee "demonstrates that both gentlemen are willing and ready to face malicious allegations intended to impugn their character and credibility."

Abella reiterated that President Duterte would not interfere in the senate probe.