Special Proceedings
Section 11. Subscribing witnesses produced or accounted for where will contested. - If the will is contested, all the subscribing witnesses, and the notary in the case of wills executed under the Civil Code of the Philippines, if present in the Philippines and not insane, must be produced and examined, and the death, absence, or insanity of any of them must be satisfactorily shown to the court. If all or some of such witnesses are present in the Philippines but outside the province where the will has been filed, their deposition must be taken. If any or all of them testify against the due execution of the will, or do not remember having attested to it, or are otherwise of doubtful credibility, the will may nevertheless, be allowed if the court is satisfied from the testimony of other witnesses and from all the evidence presented that the will was executed and attested in the manner required by law.
If a holdgraphic will is contested, the same shall be allowed if at least three (3) witnesses who know the handwriting of the testator explicitly declare that the will and the signature are in the handwriting of the testator; in the absence of any competent witnesses, and if the court deem it necessary, expert testimony may be resorted to.