see - sc.judiciary.gov.ph/jurisprudence/2013/july2013/199082.pdf
"x x x.
This is not the first time that the Court is confronted with the issue of
whether the Comelec has the exclusive power to investigate and prosecute
cases of violations of election laws. In Barangay Association for National
Advancement and Transparency (BANAT) Party-List v. Commission on
Elections,38 the constitutionality of Section 4339 of RA 936940 had already been raised by petitioners therein and addressed by the Court.
While recognizing the Comelec’s exclusive power to investigate and prosecute cases under Batas Pambansa Bilang 881 or the Omnibus Election Code, the Court pointed out that the framers of the 1987 Constitution did not have such intention. This exclusivity is thus a legislative enactment that can very well be amended by Section 43 of RA 9369. Therefore, under the present law, the Comelec and other prosecuting arms of the government, such as the DOJ, now exercise concurrent jurisdiction in the investigation and prosecution of election offenses.
x x x."
