MANILA, Philippines -- To avoid any suspicion of a whitewash, Agrarian Reform Secretary Nasser Pangandaman should refrain from defending his sons accused of beating a businessman and his son at a golf club in Antipolo, Senator Francis "Kiko" Pangilinan said on Monday.

Pangilinan said a Cabinet secretary of the Arroyo government speaking for the accused even if they were his children could only duly influence the course of the ongoing investigation.

"In the interest of a having an impartial investigation on the incident, I advise Secretary Pangandaman to refrain from issuing statements defending his sons," said the senator in a statement.

“Let the accused, one of which is a mayor of Masiu, Lanao Del Sur, defend them," he said.

Being an alter ego of the President, Pangilinan said, any move that Pangandaman would make to intercede in the controversy could be suspected as "exerting undue pressure to whitewash the case.

"A possible whitewashing of the case will just reinforce the public's perception that the influential and powerful in this country are indeed untouchables," he said.

"Let the rule of law prevail and punish swiftly those responsible for the shameful act," he further said.

The senator also reminded Pangandaman that as a public figure, he shoud exercise utmost restraint even in the face of provocation.

Abusive public officials, especially those with bodyguards, he said, could not just be allowed to roam in public brandishing their firearms and using them to intimidate ordinary citizens.

Pangilinan also lamented that the simple misunderstanding resulted into a brawl that reportedly caused serious physical injuries to businessman Delfin de la Paz, 56, and his 14-year-old son.