(a) Notwithstanding Section 827, the child welfare agency is authorized to permit its files and records relating to a minor, who is the subject of either a family law or a probate guardianship case involving custody or visitation issues, or both, to be inspected by, and to provide copies to, the following persons, if these persons are actively participating in the family law or probate case:

1. (1) The judge, commissioner, or other hearing officer assigned to the family law or probate case.
2. (2) The parent or guardian of the minor.
3. (3) An attorney for a party to the family law or probate case.
4. (4) A family court mediator assigned to a case involving the minor pursuant to Article 1 (commencing with Section 3160) of Chapter 11 of Part 2 of Division 8 of the Family Code.
5. (5) A court-appointed investigator, evaluator, or a person conducting a court-connected child custody evaluation, investigation, or assessment pursuant to Section 3111 or 3118 of the Family Code or Part 2 (commencing with Section 1500) of Division 4 of the Probate Code.
6. (6) Counsel appointed for the minor in the family law case pursuant to Section 3150 of the Family Code. Prior to allowing counsel appointed for the minor in the family law case to inspect the file, the court clerk may require counsel to provide a certified copy of the court order appointing him or her as the counsel for the minor.