Naomi Campbell and Vladislav Doronin slept in separate bedrooms before their split.
The supermodel and Russian billionaire were reported this week to have separated after around five years together, and it has now been claimed they had been sleeping apart for several weeks as their arguments increased.
A source told the New York Post newspaper: ''They've been fighting for a while. It's been going on for six months or nine months. They've been sleeping in separate bedrooms and split for a few weeks.''
The couple reportedly clashed as they live completely different lifestyles.
The insider added: ''Naomi likes to live by her own rules, stay out late, be a free spirit, while Vlad is more regimented. He is up early, works hard, does yoga and is super healthy.''
It was previously claimed that Naomi, 42, had grown tired of the 50-year-old property and hotel mogul and his obsession with the ''celebrity lifestyle''.
While the catwalk queen considers attending glamorous events with her A-list friends - including Leonardo Dicaprio and P. Diddy - work, the property mogul has reportedly been revelling in the lavish party lifestyle Naomi introduced him to.
A source said: ''He loves being around the celebrities. He loves going to the parties.''