Rihanna says rumours of a romance with Jay-Z are "crazy".

The 'Umbrella' singer has denied anything other than professional involvement with the rapper, who has mentored the 20-year-old singer since the early stages of her career.

Dismissing the rumours, the Barbados-born singer said: "I get asked about it all the time and I'm like, 'You are asking, but you know the answer.' I don't even like to address it anymore, it's crazy that the press ask me that. People know that it's not true."

Rihanna - who has previously been romantically linked to actor Josh Hartnett - also refused to comment on a budding romance with singer Chris Brown, but admitted they were "very close".

She added to America's Elle magazine: "We've always been friends, but we are very close now."

The 20-year-old singer previously said she avoided dating men in the entertainment industry, as they would never get to see each other.

She said: "If I was dating someone who wasn't in this industry they would be in the same place, all the time, so I could go back to that place and know where they were. If they did what I do we'd both be travelling at the same time and we would never see each other."

Rihanna is on tour in the US throughout May and June. (c) BANG