National Bureau of Investigation (NBI) Director Melvin Matibag on Tuesday raised concerns over the legitimacy and legal basis of a Senate Blue Ribbon Committee hearing led by Sen. Alan Peter Cayetano.

Matibag was referring to the 4 June hearing on the flood control probe, where 18 alleged former bodyguards of former lawmaker Zaldy Co were present.

He said any legal question would depend on whether the proceedings were properly sanctioned by the Senate and fall within authorized legislative functions.

Matibag, in an interview with DZRH, clarified he was speaking as a lawyer and not issuing a formal finding that the proceedings were illegal.

“I did not declare that it is illegal. What I said was that it may be proven illegal if it turns out that the hearing lacks Senate sanction,” Matibag said in Filipino.

He also said parliamentary immunity applies only to official legislative functions.

“Parliamentary immunity only extends to official functions of the legislature,” he said.

Matibag added that holding the event outside Senate premises could raise questions on its official character and authority.