The 35-year-old singer, who recently rekindled her romance with Lewis Hamilton, is good friends with the 'Purple Rain' hitmaker, reported Daily Mirror.
"Nicole was at another awards do attended by Prince Charles then went to see Prince in Camden. When the gig was over Prince went to his hotel in one car at 1am and Nicole pulled up shortly after with four minders. She stayed for a couple of hours," a source said.
Prince played two surprise shows in England's capital treating fans to new material and his greatest hits. More than 800 people were allowed in the intimate venue in north London.