Rapper Jay Z reportedly has a separate phone just for singer Rihanna.

Jay Z has a close relationship with the `Diamonds` hitmaker and his wife Beyonce Knowles was said to be "livid" when she discovered about the special line, reports femalefirst.co.uk.

"Jay has several phones, one of which he keeps reserved for Rihanna, supposedly to discuss business interests. It's obvious when she calls because he'll interrupt meetings, even walk away from the dinner table to speak with her.

"Beyonce has always been aware that he has several different numbers, but when she discovered Rihanna has a hotline to her husband, she was livid. She absolutely hates how close they are but feels powerless to stop it," a source said.