Neighbours have identified this man as the brother of the three women thought to have fled to Syria with their nine children.
It is thought that police were already concerned about his whereabouts.
The family's lawyer has urged him to get in touch and send them back if they have crossed the Syrian border.
Speaking from Pakistan, one of the husbands of the missing Bradford thought to be heading to Syria has told ITV News of his worry.
Here's what we know about the Bradford family of 12 who are feared to be travelling to Syria.