MANILA, Philippines - House Speaker Prospero Nograles on Sunday, dared poll fraud whistle blower "Robin" who came to be known as "Koala Bear" to show his face and lend more credence to his claims.

Nograles said Robin will be a more credible witness if he reveals his identity. Until he unmasks himself, his allegations will not be taken seriosuly, added Nograles.

"Yang Koala, Koala na yan unless he removes his mask, he's just a bear," said Nograles.

He also dared the media to dig deeper into the issue and find out the identity of Robin.

In a related development, former Environment Secretary Lito Atienza, who lost in the mayoral race in Manila, denied he was among those named by Makati Representative Teodoro Locsin as having supplied the video of Robin.

"I don't know who he is, I don't know what they are saying, I was shocked to hear na nasama pangalan ko, I have my own witness na babae," said Atienza.

Locsin, chairman of the House committee on suffrage and electoral reforms, tagged former executive secretary Eduardo Ermita as the Palace official who supplied the video of Robin.

He also said that Atienza, and Defense Secretary Norberto Gonzales appear to have knowledge about the expose of Robin.