According to newspaper reports, the couple were driven back to the 24-year-old's apartment in Clarence House after a night of clubbing that ended at 4am. The smouldering 28-year-old brunette reportedly emerged the following morning as Harry headed off to meet his brother William and Will's girlfriend Kate Middleton at a polo event.
Both the Prince's spokesman and Caroline's has refused to comment on their relationship. A friend told the Daily Mail, however: "Harry thinks she is cute and the feeling is mutual."
The pair having been exchanging flirty texts messages since meeting in April. On Saturday they partied at the Troubador nightclub in West London where the Prince amused Caroline by joining the band on stage to play the bongos.
Harry has been single since his five-year romance with Chelsy Day ended earlier this year, while Caroline split with musician Dave Danger in February.