This leaves a fifth SISA complaint against Singson still pending with the Ombudsman.
In the fourth dismissed case, the Ombudsman said the complainants "failed to establish by manifest and convincing evidence" that Singson and the other respondents allegedly violated the anti-plunder law "by the acquisition of ill-gotten wealth through the misuse of public funds in the total value of P900.905 million."
SISA, headed by Nestor Segismundo, charged that Singson and other provincial officials during his term as governor misappropriated the said public funds.
The Ombudsman said it found "no sufficient ground to engender a well-founded belief that the offense charged has been committed, and that public respondents are probably guilty thereof, and should be held for trial."
SISA relied on a supposedly incomplete 2000 report of the Commission on Audit on the operations of the provincial government showing expenditures amounting to P596.8 million as "suspensions" and P304 million as "disallowances."
The funds, largely defrayed for the construction of computerized tobacco flue-curing barns, were not supported by sufficient documentation at the time of the audit. Singson said the former provincial accountant, Caroline Pilar, failed to prepare the documents on time.
Pilar reportedly could not attend to her duties and took leaves of absence then to prepare for her impending marriage to a US national.
Singson expressed elation at the dismissal of the fourth complaint, saying the cases were meant to harass him and destroy his credibility as key witness in the plunder trial of deposed President Joseph Estrada in the Sandiganbayan.
"But they did not succeed," he said.