Mother missing with three-year-old son has 'gone underground'

A mother missing with her three-year-old son for six months has "gone underground", lawyers have said.Ellie Yarrow-Sanders, 26, has not used her bank accounts or mobile phone since disappearing with Olly Sheridan, according to solicitors representing the youngster's father.Patrick Sheridan, 45, has said Christmas was "unbearable" not knowing where his son is.