Filmmaker Rob Reiner and his wife, Michele Singer Reiner, were found dead in their Los Angeles home Sunday, according to a source close to the Reiner family.

The source said the couple appeared to have died from stab wounds.

Los Angeles police officials said Sunday they responded to a report of two deceased at Reiner`s Brentwood home but did not identify them. Police said a "death investigation" is underway.

Paramedics were called to Reiner`s home on the west side of Los Angeles around 3:30 p.m. A few minutes later, police officers were dispatched.

Deputy Police Chief Alan Hamilton told reporters that the investigation will continue through the night. He did not confirm the identities of the victims, saying the city coroner`s office will release that information later.

Hamilton said that officials have not identified a suspect and that no one has been detained. Asked whether police have interviewed family members, Hamilton said many family members will be interviewed.

The street where Reiner`s home is located was blocked off with caution tape, and several police cars were stationed in the area Sunday evening. Police said they will provide an update on the investigation Monday morning.

A medical examiner`s van arrived at the property and plainclothes officer was seen working at the scene in the early hours of Monday.

Reiner, 78, was a longtime actor and director known for his films "The Princess Bride," "When Harry Met Sally" and "A Few Good Men," which was nominated for an Academy Award for best picture.

This year, Reiner appeared in four episodes of the Hulu TV show "The Bear" and in "Spinal Tap II: The End Continues," which he also directed.

Rob Reiner and Michele Singer Reiner, 65, shared three children.

Tracy Reiner, Rob Reiner`s adopted daughter from his marrige to ex-wife Penny Marshall, said the news of her father`s passing stunned her.

"I came from the greatest family ever," she said. "I don`t know what to say. I`m in shock."

NBC News has reached out to a representative for Reiner for comment.

As news broke Sunday, many in Los Angeles expressed their condolences to the Reiner family.

Los Angeles Mayor Karen Bass called the deaths "a devastating loss for city and our country," saying she is "holding all who loved Rob and Michele in my heart."

"An acclaimed actor, director, producer, writer, and engaged political activist, [Rob] always used his gifts in service of others," Bass said in a statement, adding that "he and Michele fought for early childhood development and marriage equality, working to overturn Proposition 8. They were true champions for LGBTQ+ rights."

Actor Kathy Bates, who worked with Reiner on the 1990 film "Misery," said she was "horrified hearing this terrible news."

"Absolutely devastated," she told NBC News in a statement. "I loved Rob. He was brilliant and kind, a man who made films of every genre to challenge himself as an artist. He also fought courageously for his political beliefs. He changed the course of my life. Michelle was a gifted photographer. She shot my beautiful photos for the Misery campaign. My heart breaks for them both. My thoughts are with their family."

California Gov. Gavin Newsom also expressed his condolences.

"Rob was the big-hearted genius behind so many of the classic stories we love, with projects as wide-ranging as `The Princess Bride` to `A Few Good Men,`" Newsom said in a statement. "His boundless empathy made his stories timeless, teaching generations how to see goodness and righteousness in others - and encouraging us to dream bigger."