Los Angeles - Nicole Scherzinger and Lewis Hamilton have reportedly split up.
The 26-year-old Formula 1 driver and the 33-year-old singer are thought to have broken up after four years together due to "unworkable" schedules and a lack of recent face-to-face contact with each other.
A source told the Daily Mirror newspaper
: "Nicole and Lewis are both extremely busy people who lead incredibly hectic lives.
"Of late, their schedules have proven pretty unworkable and they have not been able to see as much of one another as they would have liked.
"They still speak on the phone but this isn't the same as face-to-face contact and things have been rough for the past six weeks. Both want it to work but it's fair to say things are rocky. But they have rowed before and worked things out.
"As far as both are concerned, there is still hope."
California vs the world
Lewis is often travelling around the world racing for the McLaren Formula 1 team, while Nicole - who rose to fame as a singer in girl group Pussycat Dolls - is based in Los Angeles, California, and works as a judge on TV talent show US X Factor.
In July there were unconfirmed rumours the pair were engaged
- and the sportsman recently said he wasn't planning to have a baby with the pop star due to concerns it would turn him into a less "risky" Formula 1 driver.
When asked if he has any plans to have kids, he explained: "I'm still young and I'm not in that position yet. It's a long way away.
"I think being slightly more risky in some ways is what separates the faster drivers from maybe the not-so-faster drivers."