Nick Reiner, son of the late Hollywood director Rob Reiner and Michele Singer Reiner, has been arrested on suspicion of murder after his parents were found dead at their Los Angeles home.
The LA Sheriff's Department confirmed on Monday that Nick Reiner was in custody and being held on a $US4 million ($6m) bail agreement.
Rob and Michele Reiner were found dead in their Los Angeles home on Sunday afternoon, US time.
Police are continuing to investigate the circumstances of their deaths, which they are treating as a homicide.
"We have our robbery homicide division handling the investigation," LA police chief Jim McDonnell told reporters.
"They worked throughout the night on this case and were able to take into custody Nick Reiner, a suspect in this case. He was subsequently booked for murder."
Prison records seen by Reuters said the 32-year-old was arrested on Sunday and then taken to the Los Angeles County Jail.
Representatives from the Reiner family did not immediately respond to a request for comment from the Associated Press.
It was also unclear if Nick Reiner had legal representation.
The 32-year-old has worked as a screenwriter and co-wrote the screenplay for the 2016 film Being Charlie, which his father directed.
Tributes pour in
Tributes have poured in for Reiner, who championed liberal causes and was active in politics.
"This is a devastating loss for our city and our country. Rob Reiner's contributions reverberate throughout American culture and society, and he has improved countless lives through his creative work and advocacy fighting for social and economic justice," Los Angeles Mayor Karen Bass said.
Reiner directed classic films including 1984's rock music mockumentary This is Spinal Tap, fantasy gem The Princess Bride from 1987, and the 1992 courtroom drama A Few Good Men.
His films spanned everything from laugh-out-loud comedy to searing drama and earned him a global following.
Michele Reiner was at one time a photographer who captured the image of Donald Trump that appears on the cover of his book "Trump: The Art of the Deal."
Rob Reiner was politically active and an outspoken supporter of progressive causes — potentially a reason for the extraordinary statement by US President Donald Trump on Monday, less than a day after the killings.
While movie fans around the world grieved, Mr Trump posted online that Reiner died "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".
"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," the president wrote.
Reuters/AP/AFP