California Code, Elections Code - ELEC § 15551

If a contest or any such criminal prosecution has been commenced prior to the date fixed for its destruction, the package containing the voted ballots shall be subject to the order of the court in which the contest or criminal prosecution is pending and shall not be destroyed until after final determination of the contest or criminal prosecution.

In the case of a congressional election contest, the elections official shall hold the ballots of that congressional district in custody subject to the inspection of any committee of the House of Representatives having in charge the investigation of the contest, until the final determination of the contest by the House of Representatives.

In the case of a contest in the State Legislature, the elections official shall hold the ballots of the Senate or Assembly district in custody subject to the inspection of any committee of the Senate or Assembly having in charge the investigation of the contest until the final determination of the contest or the final adjournment of the session of the Legislature in which the contest is filed, whichever is the later.

In no event shall the package or its contents be taken from the custody of the elections official.