MANILA - Customs Commissioner Nicanor Faeldon on Tuesday admitted that he was aware of the "tara" (grease money) system long before he assumed his post.

However, Faeldon said he was not able to investigate the existing system because he had no teammates to help him look into such large-scale corruption scheme.

"The appointment of the officers in charge in the probe was just December or January. So for the first 6 months, I was working alone," he said during the resumption of the probe on the shabu shipment.

• READ: After hospital confinement, Faeldon attends Senate probe

The Customs chief stressed that it would be very hard for him to man all ports in the country and conduct investigations simultaneously.

"Admittedly I failed to investigate it because I cannot do it alone. I was the only one appointed up to late last year. The people I have worked with there are the people I suspect doing the tara," he said.

Faeldon said since Day 1, he has been asking businessmen and importers to identify people asking them for tara so the government could address the problem.

"12,000 po sila (importers). Nakikiusap ako, please go to my office and tell me who are these people asking for tara. Until today, none of the 12,000 importers have come up with a name of any official of the bureau," he said.

Faeldon and other Customs officials have been under fire for alleged gross incompetence for failing to stop the entry of P6.4 billion worth of illicit drugs from China.

Senator Antonio Trillanes IV previously alleged that Faeldon, his former comrade, was "at the heart" of the P6.4-billion shabu smuggling controversy hounding the Customs.

The allegations by Trillanes prompted Faeldon to initially refuse to answer the Senator during Tuesday's probe. The senator in return threatened to cite Faeldon in contempt.

• WATCH: Faeldon refuses to answer fellow ex-mutineer Trillanes

"The accusations against innocent people have been done. It is my responsibility not to allow this to happen to these innocent people working so hard under the Customs," an emotional Faeldon said.

But after a brief recess, Senator Richard Gordon convinced the Customs chief to cooperate and answer Trillanes' questions.