Gervacio said he will assign the case to Deputy Ombudsman for the Visayas Primo Miro.
"I will only look into the matter," he said. "But to avoid any suspicion, I will inhibit myself from the investigation."
The graft case was filed against Zuño after he allegedly "influenced" the filing of a swindling case against one Joy Valenzuela Gutierrez by the Batangas Health Multi-Purpose Cooperative.
Zuños physician-wife, Eden, was said to be a member of the cooperatives board of directors.
Gutierrez was accused of defrauding the cooperative of "millions of pesos."
However, Zuño branded as "baseless" the charges against him, saying that he acted on the case of Gutierrez in accordance with the evidence submitted.
The case graft case against Zuño was filed by Aren Gutierrez, husband of the woman facing charges of swindling filed by the cooperative. Jose Rodel Clapano