MANILA - Senators on Tuesday granted legislative immunity to 3 witnesses as the chamber dug deeper into the alleged multi-billion-peso corruption at the Philippine Health Insurance Corp. (PhilHealth).

The move will allow board member Alejandro Cabading, resigned anti-fraud legal officer Thorsson Montes Keith, and former executive assistant Estrobal Laborte to speak even more freely on alleged corruption schemes within the state-run health insurance company.

Senate President Vicente Sotto III also approved the recommendation to place them under the government's witness protection program.

Sen. Panfilo Lacson earlier moved for the grant of immunity, which was promptly approved by senators sitting as a committee of the whole.

Keith had alleged that corrupt PhilHealth officials pocketed some P15 billion in the company's funds. Cabading, a certified public accountant, also pointed to an alleged 'mafia' running corruption schemes within the agency.

Laborte, a former assistant of PhilHealth president Ricardo Morales, appeared at Tuesday's Senate hearing, detailing his questions over the planned purchase of an "obsolete" computer network.

• PhilHealth officials tried to buy 'nearly obsolete' network switches for P320K each: ex-official

Later in the hearing, Morales told senators that the agency "needs a large-scale revamp."

"We were looking for a global consulting firm that could help us in the transformation because the skills necessary, the experience necessary to transform PhilHealth, cannot be found within PhilHealth. It has to be sourced outside," he said.