(a) Upon receipt of a claim, the district director shall ascertain whether the claim was filed by or on account of a miner as defined in § 725.202, and in the case of a claim filed on account of a deceased miner, whether the claim was filed by an eligible survivor of such miner as defined in subpart B of this part.

(b) In the case of a claim filed by or on behalf of a miner, the district director shall, where necessary, schedule the miner for a medical examination and testing under § 725.406.

(c) In the case of a claim filed by or on behalf of a survivor of a miner, the district director shall obtain whatever medical evidence is necessary and available for the development and evaluation of the claim.

(d) The district director shall, where appropriate, collect other evidence necessary to establish:

(1) The nature and duration of the miner's employment; and

(2) All other matters relevant to the determination of the claim.

(e) If at any time during the processing of the claim by the district director, the evidence establishes that the claimant is not entitled to benefits under the Act, the district director may terminate evidentiary development of the claim and proceed as appropriate.