Paranormal investigator Lorraine Warren, whose decades of ghost-hunting with her late husband Ed inspired horror films such as The Conjuring and The Amityville Horror, has died aged 92.
During their 61 years of marriage, the couple investigated more than 10,000 cases in the US and abroad, often writing about their experiences.
Their son-in-law, Tony Spera, said Mrs Warren died in her sleep on Thursday night at her Connecticut home.
"She was a remarkable, loving, compassionate and giving soul," Spera wrote.
The Warrens founded the New England Society for Psychic Research in Monroe, Connecticut, in 1952 to investigate suspected hauntings. The society shared its own post mourning the passing of one of its founders.
The Warrens' unusual profession has been credited with sparking popular interest in the paranormal, as well as the television shows and films now dedicated to the subject.
"When nobody was really even talking about ghosts, they were just two people from Bridgeport, Connecticut, who came together and fell in love and Ed happened to have had a lot of paranormal instances when he was growing up and Lorraine was always the sensitive clairvoyant," Horror News Network's Larry Dwyer said.
He said the couple realised they could use their "gifts" and Catholic faith to help people who believed they were being tormented by ghosts or demons.
For more than half a century, religious authorities repeatedly called on them during outbreaks of demonic phenomena, including alleged cases of priests being possessed,
Mr Warren died in 2006 and Spera now oversees the New England Society for Psychic Research.
The organisation's website said Mrs Warren had "decided to retire from active investigations regarding the areas of haunted homes and demonic infestations/possessions" but was still a consultant to the organisation at the time of her death.
The Warrens' work did receive criticism from doubters over the years.
Mrs Warren told the Associated Press in a 2013 interview that she understood it was very difficult for people to accept she could see ghosts if they had never seen one themselves.
"I hope you never will," she said. "I really don't."
The 2013 film The Conjuring is based on the couple's investigation into alleged events at a Rhode Island farmhouse in the 1970s.
Mrs Warren visited the set during the filming.
She also spent time at her Connecticut home with actress Vera Farmiga, who portrays her in the movie and its sequels.
Farmiga expressed her condolences on Twitter on Friday, saying she was "blessed to have known" Mrs Warren and "honoured to portray her".