Rob Reiner and his son Nick Reiner reportedly got into a heated argument on Saturday night

One source told the publication: "Nick was freaking everyone out, acting crazy, kept asking people if they were famous."

Rob and his wife left the star-studded party following the argument, TMZ reports.

The married couple were later found dead at their home, and Nick was subsequently arrested and charged with murder. He is now being held without bail.

News of the argument emerged shortly after US President Donald Trump took to social media to react to the tragedy.

The billionaire businessman wrote on the Truth Social platform: "Rob Reiner, a tortured and struggling, but once very talented movie director and comedy star, has passed away, together with his wife, Michele, reportedly due to the anger he caused others through his massive, unyielding, and incurable affliction with a mind crippling disease known as TRUMP DERANGEMENT SYNDROME, sometimes referred to as TDS.

"He was known to have driven people CRAZY by his raging obsession of President Donald J. Trump, with his obvious paranoia reaching new heights as the Trump Administration surpassed all goals and expectations of greatness, and with the Golden Age of America upon us, perhaps like never before. May Rob and Michele rest in peace (sic)"

Prior to that, former US President Barack Obama paid a glowing tribute to the filmmaker.

Obama - who has been married to his wife Michelle since 1992 - wrote on X: "Michelle and I are heartbroken by the tragic passing of Rob Reiner and his beloved wife, Michele. Rob's achievements in film and television gave us some of our most cherished stories on screen. But beneath all of the stories he produced was a deep belief in the goodness of people-and a lifelong commitment to putting that belief into action. Together, he and his wife lived lives defined by purpose. They will be remembered for the values they championed and the countless people they inspired. We send our deepest condolences to all who loved them."