In any action in which the custody of or the visitation with a child is a relevant fact and at issue, the court may order the mother, the child or father to submit to blood, saliva, urine or any other test deemed necessary by the court in determining that the custody of or visitation with the child will be in the best interests of the child. If so ordered and any party or child refuses to submit to such tests, the court may enforce its order if the rights of others and the interests of justice so require unless such individual is found to have good cause for refusing to cooperate.
Okla. Stat. tit. 43, § 110.2