MANILA, Philippines — Sen. Ronald dela Rosa said that former president Rodrigo Duterte would attend a Senate investigation into his administration's campaign against illegal drugs if invited.

Dela Rosa said that the former president was more comfortable in the Senate than in the House of Representatives.

Dela Rosa said he has not spoken to the former president yet but was aware that he was prepared to attend the Senate hearing if the Committee on Public Order and Dangerous Drugs, which the senator heads, would invite him to discuss the controversial issue.

Dela Rosa said that if anyone refused to appear before the House Quad Committee hearings on the drug war, his committee was open for them.

According to Dela Rosa, the hearing he will convene will involve checks-and-balances with the House hearing. The Senate inquiry may be held during this congressional break.

He said he was not concerned about the House QuadComm investigation because his conscience was clear, and there was no strong evidence against him.

"I have no fear. I am not directly involved in any way, except maybe in my official capacity as the Chief PNP (CPNP). However, I can't monitor all my police 24/7 and what they do. Perhaps I have command responsibility as a CPNP. But if you say I have a direct hand in what is being done or what happened, I don't think they will link me," remarked Dela Rosa.

Dela Rosa vehemently denied that they had a reward system when he was PNP chief.

"I don't know that. If that happened, maybe they do it in a secretive manner that the people don't know about. But, honestly, I was not involved if there was anything like that. But ask me if that exists. I can't even say it exists because it's not to my knowledge," the senator stressed.