As police probe circumstances leading to Sunanda's death at a city hotel, the on-board fight points to differences that clearly persisted despite the couple's joint statement that claimed their marriage was intact. 

This open display of differences between the couple, sources said, was seen by I&B minister Manish Tewari, who sat across the aisle from the couple. Tewari boarded the flight at Mumbai where he had attended a function. 

Piecing together details of what happened in the aircraft and at the hotel, police feel the Tharoors virtually fought non-stop for about 72 hours over Tarar before Sunanda's death. "Differences had been brewing over six months but aggravated in the last two. She was extremely depressed and angry in her last three-four days," a source said.