The NBI has accused Singson of being unable to liquidate some P120 million in cash advances.
"We might toss the case to the Ombudsman similar to what we have done in the previous charge," said Chief State Prosecutor Jovencito Zuño.
He added that he will take up the matter with Justice Secretary Artemio Tuquero this week to see if a preliminary investigation is needed.
Zuño, along with Assistant Chief State Prosecutor Apolinario Exevea and State Prosecutor Ruben Carretas, turned over to the Ombudsman last December the P170-million plunder case against Singson and 15 other Ilocos Sur officials.
The justice department said the Ombudsman "has the primary and appropriate authority to act" on the P170-million case since "similar complaints have also been filed (with the said office) involving the same transactions."
The new plunder case stemmed from two unliquidated cash advances, one involving P100 million from the tobacco excise taxes supposedly for "various projects," while the remaining P20 million was for the flue curing barns and equipment for a redrying plant.
The NBI said the funds taken from the province’s share of excise taxes were not accounted at all, despite repeated demands by the provincial auditor. The bureau said this is in violation of Section 48 of Circular 92-382 of the Commission on Audit.
The COA circular provides that when a "cash advance is no longer needed or has not been used for a period of two months, it must be returned or deposited immediately with the collecting officer."
Failure to give an accounting of the cash advance "raises the legal presumption and probable case that he (Singson) squandered the said public money for himself. Otherwise, he could have liquidated or restored the said amount," the NBI said.
Singson’s co-respondents are Vice Gov. Deogracias Victor Savellano, accountant Carolyn Pilar, treasurer Antonio Gundran and budget officer Erlita Arce.
On the previous plunder charge, Zuño and his colleagues inhibited themselves from conducting the probe after defense lawyers questioned their impartiality, citing that the justice department is under the executive branch of government.
"Considering that the DOJ belongs to the executive branch… the respondents (Singson and the others) have expressed no confidence that this panel of prosecutors can handle with impartiality the investigation," the lawyers said.  Delon Porcalla