If your organization is in the United States or other countries with well-established child abuse reporting laws, then reporting is simple. You report according to your statute, usually when you have a reasonable suspicion of abuse. It may not be pleasant, but it is straightforward. The only proper approach to protect children and for the organization is to make that call.
If the alleged abuse happened in a country where reporting protocol is not established—or you have a multijurisdictional nightmare—or abuse that is historic—it may not be clear whether and how to report. What if you are based in the United States and there seems to be no jurisdiction over the abuse, because of issues of geography or the allegation is old? You can still make reports in the state where the alleged offender is, the state where your organization is, or the alleged victim is. While it may be unlikely that these reports are acted on directly, the information is often filed for the future protection of children.
Another possibility, if the alleged abuse is current, is to report to border protection officials. This should happen before the member of the mission who is alleged to have committed abuse returns to the United States. Depending on the seriousness of what is alleged, the Department of Homeland Security may act on your tip and call the person in for screening or questioning at the airport. If child pornography or child sexual abuse is alleged, officials may do a search of the electronic devices the person is carrying. Reporting in this way is going to be most effective if a serious crime is alleged, such as child pornography or child sexual abuse.
To report criminal activity of this nature, call 866-DHS-2-ICE (866-347-2434). This number works in North America. For other areas of the world, call 802-872-6199.
Still another option might be to discuss the allegations of abuse with your embassy, or the embassy of the alleged offender.
Reporting in these various ways can be an effective way to protect children. You may want to have legal counsel before making reports of any kind, because the wording of the report is important. All reports must be made in good faith, and reports in unusual situations may not provide you with the usual statutory immunity.