When Sharon Tate's home was torn down, the ghosts of Manson's victims moved next door.

David Oman believes in ghosts. More specifically, he believes the victims of the Manson family are haunting his home.

Almost twenty years ago, the Los Angeles private investigator bought a vacant lot in Benedict Canyon, California, just 45 metres from 10050 Cielo Drive.

Cielo Drive is where on August 9, 1969, actress Sharon Tate and four others, Wojciech Frykowski, Abigail Folger, Jay Sebring and Steven Parent, lost their lives at the hands of a deranged cult led by Charles Manson. And Oman was moving in next door.

Oman hoped to build his dream home on the land, and felt he had gotten a bargain when he was only charged $40,000 USD ($53,000 AUD) for what appeared to be an idyllic plot in a prime location not far from ritzy Beverly Hills.

He may have got a bargain but he also got more than he bargained for.

The “haunting” at Oman’s property began immediately during construction, he says, with workers claiming they’d heard voices when no one was there. Cold air would dance upon the back of their necks on warm days. Heavy footsteps thudded across the floor boards in empty rooms. The building site just had a bad vibe.

No doubt the fact that it was in spitting distance from the site of one of the most notorious and brutal mass murders in America’s history didn’t help. But the house at 10050 Cielo Drive, where the Manson Family murders were committed, had been torn down long before Oman moved next door.

The original property, rented by director Roman Polanski and his wife Sharon in the year prior to her death, was demolished in 1994 and a new home built in it’s place. Even the street address was changed from 10050 to 10066 Cielo Drive in the hope of erasing the lot’s brutal history. Oman moved into his nearby property eight years after that demolition, in 2002.

Things got weird as soon as he settled in. During his housewarming party, a number of unexplainable and very creepy things occurred.

While he was putting out food for his shindig, Oman says he heard a loud, persistent knocking at his front door. It was too early for guests to arrive, but he went over and flung the door open anyway. No one was there. The entire street was dark and empty, not a single car in sight.

Later that night, as fifty guests partied though the evening, Oman's friend Lauren Rakkel says she went to the kitchen to fetch more wine, as you do. It was then she saw someone walk quickly by outside the kitchen window. There was one little problem - the edge of the hillside mansion sat ten metres off the ground. It wasn't possible for anyone to walk by unless they were ten metres tall, or could float.

In that same kitchen, a wine glass would later be hurled into the wall, shattering, when no one was in the room, Oman said.

And then it got worse. In 2004, Oman says he was awakened by what he told LA Weekly was, "a full body apparition at the bottom of his bed pointing towards the driveway which leads to the murder site."

The eerie figure made, "no sound," Oman said, "He gestured three times and then just disappeared."

Psychic detective Debbie Malone on how to tell if spirits are present. (Post continues below.)

Oman may have been able to write the experience off as a strange dream, if he hadn't later seen a photo of Jay Sebring, Sharon Tate’s hairdresser, who'd also been killed that fateful night. The man he saw materialise at his bedside looked exactly like Jay.

Oman's girlfriend Lisa Rigsbee also claims she saw the ghostly male figure, appearing at her bedside when she'd turned in early one night. She'd heard someone enter the room and turned over, expecting to see Oman. It wasn't him. As she reached for the bedside lamp, the male figure just vanished.

The odd occurrences just kept coming. Disembodied voices were heard speaking over the house's intercom system while Oman and two friends sat watching a film. He'd hear labored breathing and raspy whispers coming from inside his empty bedroom. The movie projector would turn itself on in the middle of the night. Strange lights and figures appeared on photographs.

A session with a psychic followed, and that's when things really got weird. During the psychic's visit, she claimed the apparition of a blonde woman walked from one room to another. When Oman held a seance with friends later that night, they say they heard what they described as the voice of a woman emitting the saddest, most horrible scream. Then there was silence.

Oman began looking for answers. He invited yet more psychics to the house. One such paranormal investigator was said to have seen what she described as the spirit of a bleeding, pregnant woman walking down the street, toward Oman's home. The vision later caused her to faint.

What had happened at Cielo Drive was no secret, but Oman began to wonder if there was a connection between his home and the Manson murders. He even sought the help of the LAPD to inquire if perhaps a murder weapon or traces of DNA from the victims were left on the lot where his luxurious mansion now stood. But he came up empty handed. There was no link.

It didn't make sense to Oman that, if in fact he was seeing the spirits of the Manson Family's victims, they'd somehow moved next door to the site on which they died. That's not how ghosts work, most believers will tell you.

It wasn't until later that a theory emerged. Oman wondered if the victims had called for help, desperately hoping they'd somehow be heard by people in nearby homes. If they'd attempted to escape to the street to raise the alarm.

"I began to think to myself, maybe they were trying to escape the house, and run down the driveway and seek help from the neighbours," Oman said in an episode of the SyFy channel's Paranormal Witness, centred on his experiences.

Perhaps, Oman thought, these restless spirits were still reaching out from the beyond, imploring their neighbours for help.

Oman continues to live at the home to this day. He has opened it up to dozens of paranormal investigators and psychics, hoping for an answer. He even allows ghost tours through the property.

The home is said to be a hub of ghostly activity. Some psychics theorise the site sits atop an Indian burial ground, or is a "portal" to the other side. It's has even been nicknamed the "Mount Everest of Haunted Houses".

But Oman's claims are not without controversy, and there are those who believe the detective could be unfairly profiting from tragedy with tall tales of spooks and hauntings.

Over time, Oman says he has grown used to his ghostly companions, whoever they may be.  “I always felt like I wasn’t alone here, but I’m not afraid," he told LA Weekly. "And I do know life is more than just what we see. Besides, I’m way more scared of the living than the dead".