TMZ spoke with Jenni Weinman, a rep for the estate and Lara's family -- who tells us, "It is with unbearable sadness that I can confirm that Lara Long, the sister to DJ AM passed away late Monday night, May 9th after a fierce four month battle with an extremely rare colon cancer."
Weinman continues, "She was just two months shy of turning 41. Lara was responsible for keeping the memory of her brother alive with the creation of the DJ AM Memorial Fund. She was the driving force behind his eBay shoe sale as well as his record sales, working tirelessly to make sure he would not be forgotten.
"Lara was an amazing woman, with a huge personality, a heart of gold and an incredible laugh. There are no words to explain how she will be missed. We ask that you please respect the privacy of the family at this most devastating of times.”