Davao City Vice Mayor Paolo Duterte and Atty. Manases Carpio, the husband of Davao City Mayor Sara Duterte, on Monday said they will be attending the Senate investigation into the P6.4-billion illegal drug shipment from China.

In a statement, Paolo Duterte and Carpio said they have received an invitation to attend Thursday's Senate Blue Ribbon Committee hearing.

"We duly recognize the coercive powers of the Senate of the Philippines as part of the legislative branch of government and their authority to conduct an inquiry in aid of legislation. We commit to respect the invitation and attend the hearing," they said.

In a Senate hearing, customs broker Mark Taguba had said the younger Duterte and his brother-in-law, Atty. Manases Carpio, were "name-dropped" by individuals who paid "grease money" to Customs officials for the release of shipments.

But Taguba has since cleared the Vice Mayor and Carpio of any involvement in alleged corruption at the Bureau of Customs.