London ; Mama Cass Elliot , ( centre ) a member of the American pop singing quartet , ' the Mamas and the Papas ' is escorted by plain clothes policeman and woman after arriving by train at Waterloo Station here last night . Mama Cass was arrested on a charge of larceny . Earlier in the day , Cass and the other three members of the group arrived at Southampton on the liner , ' France ' . Within minutes of disembarking a man walked up to Cass and said he was arresting her for something she had done when she was visiting England in April . The group is one of the most popular in America and in England . 6 October 1967