Amy Winehouse
Amy Winehouse's cause of death is still a mystery. Toxicology reports revealed were "no illegal substances" in her body at the time of her death, the singer's family said. . Reuters

Jazz and pop recording artist Tony Bennett said Amy Winehouse knew her alcohol addiction was going to kill her, even though other people didn't realize it.

In an interview with Jon Stewart on The Daily Show, Bennett praised Winehouse, saying she was a great singer in the tradition of Dinah Washington.

Winehouse's final recording, a Body and Soul duet with Bennett, was released Sept. 14 to commemorate what would have been her 28th birthday. Bennett said that during the recording in March, Winehouse was troubled so much by her alcohol addiction that she knew she wasn't going to live much longer.

She was in trouble at that time ... What people didn't realize at that time, she really knew, and, in fact, I didn't really know it when we were making the record ... She knew she was in a lot of trouble, that she wasn't gonna live. And it wasn't drugs. It was alcohol, Bennett said.

Winehouse was found dead July 23 at her London home. The reason for her death remain unexplained and nonsuspicious, according to the police.