Mick Jagger on L'Wren Scott's death: "I am still struggling to understand"

Mick Jagger is opening up about the death of his longtime girlfriend, fashion designer L'Wren Scott.

In a statement posted on his website, the Rolling Stones frontman said he is "still struggling to understand how my lover and best friend could end her life in this tragic way."

"We spent many wonderful years together and had made a great life for ourselves," he continued. "She had great presence and her talent was much admired, not least by me."

Jagger said he was "touched" by the tributes people had paid to Scott -- which came from the likes of Madonna, Vogue editor Anna Wintour and others -- as well as messages of support he has received.

He finished the message with, "I will never forget her." The post, titled "L'Wren" was accompanied by a black-and-white photo of the designer.

Scott, 49, was found dead in her Manhattan apartment Monday in an apparent suicide.

A spokesman for Jagger said he was "completely shocked and devastated by the news" of her death, and later shot down rumors that the two had recently split.

On Tuesday, the Rolling Stones canceled upcoming concert tour dates in Australia and New Zealand.