A battle for the custody of Michael Jackson's three children began brewing between the children's nanny and grandmother just hours after the pop singer was pronounced dead Thursday, according to a Jackson biographer and family friend.

The children, when previously seen in public, were always at their father's side, regularly wearing pint-sized versions of Jackson's trademark surgical mask, or shrouds over their heads to conceal their identities.

As Jackson's behavior became increasingly bizarre over the years, public scrutiny focused on the children, particularly after Jackson dangled his infant son from a hotel balcony and allegations surfaced that the singer had molested other children.

Police have not yet confirmed whether the children were at home with Jackson Thursday when he collapsed following a cardiac arrest.