The couple were last pictured together in March and earlier this month, The Sun claimed their romance was on the rocks due to their busy schedules as Grigor travels the world for tournaments and Nicole divides her time between London, Los Angeles and her native Hawaii, where she i reportedly holed up in her family home.
She's no stranger to high profile relationships as she finally ended things with Formula One superstar Lewis Hamilton in 2015 after seven years of dating on and off.
Some of The Pussycat Dolls appeared in the 2003 film Charlie's Angels: Full Throttle, dancing to Mancini's "The Pink Panther Theme".
They were also featured in Pink's "Trouble" music video.
However, despite their commercial success, the group was plagued by internal conflict due to the emphasis on Scherzinger, the group's lead vocalist, and the subordinate treatment of the other members.