DEATH, EVIDENCE OF. The Muslim law admits of the evidence of death given in a court of justice being merely by report or hearsay. The reason of this is that death is an event of such a nature as to admit the privacy only of a few. But some have advanced that, in cases of death, the information of one man or woman is sufficient, “because death is not seen by many, since as it occasions horror, the sight of it is avoided.”
If a person say he was present at the burial of another, this amounts to the same as an actual sight of his death. (Hidayah, vol iv p 678.)

Based on Hughes, Dictionary of Islam