50 Cent spent the night with Ciara in an exclusive hotel.
The 33-year-old US rapper and 23-year-old singer recently retired to one of the penthouse suites at New York's AKA Times Square Hotel and Residences on West 44th Street.
A source told the New York Post newspaper: "There was only one bed in that penthouse."
This is not the first time the pair have been romantically linked.
They met while working on Ciara's track 'Can't Leave 'Em Alone' and rumours they were dating first emerged when they posed topless together for the music promo in 2007.
Ciara said at the time: "Everybody turns everything into something else.
"They said we have a ranch in Atlanta. I just died laughing. It's amazing to hear the things people make up. It's funny."
Last year, 50 rejected claims he had married the singer in a secret ceremony after he was pictured wearing a wedding ring.
A spokesman for the rapper said: "50 Cent is not engaged or married."