NEW YORK: Rolling Stones frontman Mick Jagger said Tuesday he was “struggling to understand” girlfriend L’Wren Scott’s apparent suicide as it emerged the fashion designer’s business was grappling with multi-million-dollar debts at the time of her death.

Jagger, who was reportedly heading back to New York after the Stones canceled the opening leg of an Australian tour that was to have begun on Wednesday, described 49-year-old Scott as not only his lover but his best friend.

“I will never forget her,” Jagger, 70, wrote in a blog post on his website, a day after Scott was found dead at her luxury New York apartment after her suspected suicide.

“I am still struggling to understand how my lover and best friend could end her life in this tragic way,” Jagger wrote under a post entitled simply “L’Wren,” featuring a black and white photo of the former model.

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

“I have been touched by the tributes that people have paid to her, and also the personal messages of support that I have received. I will never forget her.”

Scott and Jagger, who was 21 years older, had been dating for well over a decade.

A spokesman for Jagger meanwhile angrily dismissed reports in the New York Post tabloid citing an unidentified source which said the rocker had recently broken up with Scott.

“This is a complete and utter fabrication and a result of ill-informed gossip at this tragic time for Mick. It is absurd and not true,” Jagger spokesman Bernard Doherty said.

The fate of the Rolling Stones’ sold-out tour to Australia and New Zealand was in limbo following Scott’s death.