Michael Douglas has recalled how he once had a "heartbreaking confessional" with Rob Reiner regarding their sons' troubles.
The This Is Spinal Tap director, 78, and his wife Michele Singer Reiner, 70, were found dead at their Brentwood, Los Angeles home last December.
The couple's son, Nick Reiner, has been charged with two counts of first-degree murder over their deaths. He has pleaded not guilty and is awaiting trial in custody.
On Monday, The Los Angeles Times published an excerpt from Michael's new memoir, One Helluva Ride, in which the Oscar-winning actor described a conversation he once had with Reiner.
"We both had sons with serious drug issues and we both, at times, had been at the end of our rope," he writes, according to the outlet. "It was a heartbreaking confessional for us, but I know we gave each other some measure of comfort during the hard times."
Previously, Rob had discussed Nick's substance abuse issues and rehab stays. The pair made the 2015 film, Being Charlie, about his experiences.
Meanwhile, Michael's eldest son, Cameron Douglas, also struggled with drug addiction and was arrested in 2009. The actor, now 47, spent around seven years in prison, with two of those years in segregated housing.
Cameron has been sober since his release from jail and penned a book, Long Way Home, in 2019.
Previously, Michael opened up about his connection with Rob, whom he worked with on the films The American President and And So It Goes, in a CBS News special that aired last December.
"With this terrible tragedy, we're realising how much pressure he was dealing with in his personal life with his son. I also had a son who had drug issues. And I'm happy to say he's overcome them and he's living a prosperous life. But we talked a lot about that: What you can do as a parent, what you can't do," the 82-year-old said at the time. "So knowing with all of that going on behind the scenes, this was a man who always gave you his best."
One Helluva Ride is now available.
