Their relationship soon turned romantic , according to Tito 's authorized biography , The Loves of Josip Broz Tito .
In 1940 , Haas travelled to Istanbul , Turkey , to deliver a passport to Tito , who was returning from a trip to Moscow , Soviet Union .
Their relationship soon turned romantic , according to Tito 's authorized biography , The Loves of Tito     .
In 1940 , Haas travelled to Istanbul , Turkey , to deliver a passport to Tito , who was returning from a trip to Moscow , Soviet Union .