Troubled pop star Amy Winehouse will not be allowed to perform at the Grammy Awards because her US visa application has been rejected.

The Back To Black star - currently in rehab for drug addiction - had been invited to sing at the event on Sunday. She has been nominated for six awards.

But the US Embassy in London turned down her application.

A spokesman for the star said: "Amy Winehouse will not be performing at this year's Grammy Awards ceremony.

"Unfortunately, her application for a visa to enter the United States of America has been rejected at this time by the American Embassy in London.

"Amy has been progressing well since entering a rehabilitation clinic two weeks ago and although disappointed with the decision has accepted the ruling and will be concentrating on her recovery.

"Amy has been treated well and fairly by the embassy staff and thanks everyone for their support in trying to make this happen.

"There will of course be other opportunities and she very much looks forward to visiting America in the near future."

The 24-year-old singer attended a meeting with embassy officials on Monday, accompanied by her lawyer.

In addition to her current well-documented addiction problems - she entered rehab on January 24 after a video emerged of her apparently smoking crack cocaine - she was arrested and fined in Norway last October for possession of cannabis.

Winehouse's six Grammy nominations include Record of the Year for Rehab and Album of the Year for Back To Black.