Like actress Katrina Halili, controversial cosmetic surgeon Hayden Kho has tested negative for drug use, the head of the Philippine Drug Enforcement Agency (PDEA) announced Wednesday.

"Negative din ang pagkaka-alam ko sa resulta," PDEA Director General Dionisio Santiago said in an interview on ABS-CBN’s morning show “Umagang Kay Ganda.”

Both Halili and Kho, who are involved in a sex scandal, separately underwent drug tests at the PDEA office in Quezon City Tuesday after the camp of the doctor accused the actress of influencing him to use an illegal substance.

Halili has repeatedly denied Kho’s accusations. Kho, on the other hand, admitted in last week’s Senate hearing that he began using ecstasy during his brief affair with the actress in 2007. 

The drug use allegations had prompted PDEA to look into the controversy.

Both parties tested negative for drug use but PDEA said hair sample, not urine sample, can provide a more conclusive test result. PDEA, however, is not yet equipped to analyze hair samples.

"Malaki ang pera, mga half a million, ang kailangan namin [para sa equipment]," Santiago said.

The PDEA head said Kho’s statement is vital in the agency’s efforts to go after drug pushers. The cosmetic surgeon, however, refused to divulge the name of his supplier due to security reasons, Santiago said.