Who carries out investigation for election-related criminal offenses?

Gibraltar
PARLIAMENT ACT, Principal Act No. 1950-15 Commencement date 21.7.1950 with Amending enactments (up till28.6.2007).
Miscellaneous.
Government of Gibraltar, Laws of Gibraltar OnlineService,
http://www.gibraltarlaws.gov.gi/articles/1950-15o.pdf as retrieved on 2013-09-10.
Limitation.
50.(1) Aproceeding against a person in respect of the offence of a corrupt or illegalpractice or any other offence under this Act shall be commenced within one yearafter the offence was committed, or if it was committed in reference to anelection in respect to which an election petition is presented shall becommenced within one year after the offence was committed or within threemonths after the determination of such election petition, whichever period lastexpires, so that it be commenced within two years after the offence wascommitted, and the time so limited by this section shall, in the case of anyproceeding under the Criminal Procedure Act for any such offence, besubstituted for any limitation of time contained in the last mentioned Act.
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Duties of Attorney-General.
51. Whereinformation is given to the Attorney-General that any corrupt or illegalpractice has occurred in reference to any election, it shall be his duty to make such inquiries andinstitute such prosecutions as the circumstances of the case appear to him torequire.