HOLLYWOOD, Calif. — Mandy Moore is speaking out for the first time since her ex-boyfriend DJ AM was found dead Friday inside a New York City apartment.

"I am absolutely heartbroken," the 25-year-old singer and actress said in a statement to Us Weekly. "For those of us lucky enough to have known him, Adam radiated a contagious exuberance for life and also personified the very definition of a true friend."

Moore and DJ AM dated briefly in 2007, but the pair remained close over the years.

"To say that he will be missed beyond words is an understatement," said Moore, who married rocker Ryan Adams in March. "My heart goes out to his loved ones."