Does a father's testimony that his daughter was suckled by his deceased brother's wife, along with her cousin, count as valid?

Scholars have stated that if a husband is informed that his wife has been suckled by someone whose milk makes her unlawful for him, and the informant is known for truthfulness, then he must act upon what was reported. However, if the informant is not reliable, he is not obligated to act upon their report, but it is recommended for the husband to leave his wife as a precaution for his religion.