A self-confessed drug dealer, whose father was killed in an alleged gun fight in prison, has testified before a Philippine Senate investigation that he provided police officials and an opposition senator millions of pesos in protection money.

Rolando "Kerwin" Espinosa Jr. said Wednesday that he gave 8 million pesos ($160,000) last year to Sen. Leila de Lima's bodyguard. De Lima was a former justice secretary who President Rodrigo Duterte earlier alleged had collected money from drug lords through her bodyguard, who was also her lover, to fund her senatorial campaign.

De Lima, who has initiated an investigation into Duterte's deadly anti-drug campaign, has denied receiving drug money and said she does not know Espinosa.

Duterte's anti-drug campaign has left more than 4,000 suspected addicts and pushers dead since July.