A son of film director Rob Reiner and Michele Singer Reiner has been arrested and booked on suspicion of murder after the couple were found dead in their Los Angeles home.

The Los Angeles Police Department said on Monday that Nick Reiner, 32, had been arrested and that he was in custody with no bail.

The deceased couple's 28-year-old daughter, Romy, found her parents in their home with multiple stab wounds on Sunday, sources told the BBC's US partner CBS News.

Rob Reiner is known for directing several iconic films in a variety of genres, including When Harry Met Sally, This is Spinal Tap, Stand By Me, Misery and A Few Good Men.

Emergency services were called to provide medical aid at the Reiners' Brentwood, California, home at around 15:38 local time (23:38 GMT) on Sunday.

The Los Angeles Fire Department said two people - later identified as Rob Reiner, 78, and his wife Michele, 68 - were pronounced dead at the scene.

Police said Nick Reiner was arrested several hours later, at about 21:15 local time on Sunday. Investigators have not publicly outlined a motive and said the investigation remains ongoing.

Nick Reiner has spoken publicly about his struggles with addiction and homelessness. His experiences formed the basis of the semi-autobiographical film Being Charlie, which he made with his father in 2015.

The family's home is in Brentwood, a wealthy celebrity enclave full of large mansions, boutique shops and restaurants. On Monday morning, a security guard stood outside the home as media gathered outside the front gate.

Rob Reiner, the son of comedy great Carl Reiner, began his career in the 1960s and rose to fame playing Meathead in the TV sitcom All in the Family.

He cemented his success with the cult mockumentary This Is Spinal Tap in 1984, which he directed and starred in.

Reiner was married to Laverne & Shirley actress Penny Marshall from 1971 to 1981 and is the adoptive father to Marshall's daughter, actress Tracy Reiner.

He married Michele Reiner in 1989, whom he said he met during the making of the romantic comedy-drama film When Harry Met Sally. The couple have three children together.

Michele Reiner was an actress, photographer and producer, and the founder of Reiner Light, a photography agency and production company.

Rob Reiner was also known for his outspoken political activism and support for Democratic candidates.

In a post calling their deaths "very sad", President Donald Trump criticised Reiner, saying that they "reportedly" died "due to the anger he caused others through his massive, unyielding, and incurable affliction" with "Trump Derangement Syndrome".

"He was known to have driven people CRAZY by his raging obsession of President Donald J. Trump," the president wrote.

It is not clear what reports the president was referring to, and while the investigation is being treated as a homicide, police have yet to comment on any possible motive.

The president and his allies often used the term Trump Derangement Syndrome in reference to those who are critical of him. Reiner was a vocal critic of Trump's.

Several Republicans criticised Trump over the post, including former ally Marjorie Taylor Greene, who said the deaths were a "family tragedy, not about politics or political enemies".

"Many families deal with a family member with drug addiction and mental health issues. It's incredibly difficult and should be met with empathy, especially when it ends in murder," she said.

Trump's post was also met with anger by some of the Reiners' friends.

In a post on X, Maria Shriver, the former first lady of California and longtime friend of the Reiners, said the couple were "devoted parents".

"They deeply loved all their children and they never gave up trying to care for them," she said.

Sir Elton John, who made an appearance in this year's Spinal Tap sequel, said: "I am in disbelief at today's news of Rob and Michele.

"They were two of the most beautiful people I'd ever met and they deserved better."

Fellow actor John Cusack, who appeared in Reiner's 1985 film The Sure Thing, called him "a great man", while Elijah Wood, who starred in 1994's North, said he was "horrified" by the couple's deaths.