Sec. 3. INVESTIGATION OF GROUNDS FOR APPLICATION. (a) On appointment, counsel shall investigate expeditiously, before and after the appellate record is filed in the court of criminal appeals, the factual and legal grounds for the filing of an application for a writ of habeas corpus.

(b) Not later than the 30th day before the date the application for a writ of habeas corpus is filed with the convicting court, counsel may file with the convicting court an ex parte, verified, and confidential request for prepayment of expenses, including expert fees, to investigate and present potential habeas corpus claims. The request for expenses must state:

(1) the claims of the application to be investigated;

(2) specific facts that suggest that a claim of possible merit may exist; and

(3) an itemized list of anticipated expenses for each claim.

(c) The court shall grant a request for expenses in whole or in part if the request for expenses is timely and reasonable. If the court denies in whole or in part the request for expenses, the court shall briefly state the reasons for the denial in a written order provided to the applicant.

(d) Counsel may incur expenses for habeas corpus investigation, including expenses for experts, without prior approval by the convicting court or the court of criminal appeals. On presentation of a claim for reimbursement, which may be presented ex parte, the convicting court shall order reimbursement of counsel for expenses, if the expenses are reasonably necessary and reasonably incurred. If the convicting court denies in whole or in part the request for expenses, the court shall briefly state the reasons for the denial in a written order provided to the applicant. The applicant may request reconsideration of the denial for reimbursement by the convicting court.

(e) Materials submitted to the court under this section are a part of the court's record.

(f) This section applies to counsel's investigation of the factual and legal grounds for the filing of an application for a writ of habeas corpus, regardless of whether counsel is employed by the office of capital and forensic writs.