The disturbing story behind The Conjuring that's remained hidden for 50 years.

For those who know the The Conjuring horror franchise well will be aware the films were based on real life events.

The films followed the journey of Lorraine and Ed Warren – a real life couple – who are portrayed as ‘demonologists’ with hearts of gold.

The films are bound with a single, underlying thread: That Lorraine and Ed Warren are and do good, saving victims from demonic, supernatural forces.

However, a new legal spat has revealed the real-life couple may not have been as loving and as lovely as they were depicted in the $1.2 billion-grossing horror movies.

In legal documents obtained by The Hollywood Reporter, it’s alleged producers of the well-known film were made aware of the couple’s dark history in the weeks after the first film was released in 2013.

Of the allegations, THR report in the 1960s, Ed Warren initiated a relationship with an underage girl, now in her 70s, called Judith Penney. In a sworn statement from Penney obtained by THR, it’s believed Lorraine knew of the affair.

The article alleges Penney lived with the couple as Ed's lover for four decades, living in the bedroom "opposite the one occupied by the married couple" from the age of just 15. Later, it's believed she moved to an apartment above the house that was specially built for her and that over the years, the couple told others she was either a niece or poor girl whom they had taken in out of charity.

In her declaration, Penney said in 1978, when she was in her 30s, she became pregnant with Ed's child and was forced by Lorraine to have an abortion.

In a recording obtained by THR, she states:

"They wanted me to tell everyone that someone had come into my apartment and raped me, and I wouldn't do that. I was so scared. I didn't know what to do, but I had an abortion. The night they picked me up from the hospital after having it, they went out and lectured and left me alone."

The ugly allegations have emerged due to a lawsuit lodged by a former producer on the franchise, Tony DeRosa-Grund, who is suing the franchise after he claims he was unfairly shut out of the sequels and is therefore owed profits.

In his lawsuit, DeRosa-Grund claims producers were made aware of the claims but still proceeded to sell the film as a true story.

"Ed was a pedophile, a sexual predator and an [sic] physically abusive husband," wrote DeRosa-Grund. "Lorraine enabled Ed to do this, she knowingly allowed this illegal (read criminal) relationship to continue for 40 years. They lied to the public."

While Penney said that she remained friends with Ed till his death in 2006, despite their relationship ending in 2003, she remains dissident towards Lorraine.

"As I'm older now, I can't even fathom why Lorraine let me stay there," she said in one of her many recordings and declarations during legal proceedings. Despite this she never revealed her story to the media, even during the release of The Conjuring films.

If anything, the revelations certainly cast the film and its inspiration in a different light.

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