(1) In all cases the District Judge or District Delegate may, if he thinks proper,--
(a) examine the petitioner in person, upon oath;
(b) require further evidence of the due execution of the will or the right of the petitioner to the letters of administration, as the case may be;
(c) issue citations calling upon all persons claiming to have any interest in the estate of the deceased to come and see the proceedings before the grant of probate or letters of administration.