Shocking, never-before-heard details about one of America’s most talked about cold cases will be revealed when the brother of JonBenet Ramsey speaks publicly about his sister's murder for the first time, Daily Mail Online has leaned exclusively.

Burke Ramsey was nine when when six-year-old child pageant star, JonBenet was found dead in the basement of her family’s Colorado home in December 1996,

Breaking his silence as the 20th anniversary of JonBenet’s death nears, 29-year-old Burke reveals what he knows about his sister’s mysterious murder in a ripped-from-the-headlines exclusive interview with Dr. Phil in a three-part interview that will air beginning September 12.

JonBenet was found bludgeoned and strangled on December 26, 1996, hours after she was reported missing.

She had been covered by a white blanket with a nylon cord around her neck, her wrists bound above her head and her mouth covered by duct tape. Her skull was also cracked.

Shocking details about one of America’s most talked about cold cases will be revealed when Burke Ramsey, the brother of JonBenet Ramsey speaks to Dr Phil publicly about his sister's murder for the first time, Daily Mail Online has leaned exclusively

The body of JonBenet (above in 1996), a child beauty queen, was found bludgeoned and strangled in her basement on December 26, 1996 when she was just six-years-old

John and Patsy Ramsey with JonBenet and Burke pose for family Christmas picture

Her parents, John and Patsy, had called police to report her kidnapping and said they found a note demanding a ransom of $118,000 - and ordering them to not contact authorities - if they wanted their daughter returned safely. Despite the ransom note, police arrived to their home shortly after in clearly marked vehicles.

Burke Ramsey is now 29 years old. He was nine when his sister was murdered

Hours after police searched the home, John Ramsey found JonBenet’s body in a little-used utility room in the home’s basement.

John and Patsy would remain the primary suspects in their daughter's death for more than a decade, and it was not until 2008 that police finally cleared them of any wrongdoing.

At that time, Patsy had been dead for two years after a lengthy battle with ovarian cancer.

She was initially suspected by many of being the murderer after reports emerged that handwriting on the ransom note was similar to her own, but after she willingly provided a sample to police it was determined she did not write the note.

Many also suspected the killer was someone in the family as they claimed there were no footprints in the snow around the house and the ransom amount was the exact amount that John had just received in his annual bonus.

No one in the family was ever charged in the death of the six-year-old, but for years tabloids and members of the public believed one or more were the culprits of this unspeakable crime.

Most of these stories focused on parents John and Patsy, but some went so far as to claim that JonBenet’s brother Burke had been responsible for his sister's death - despite the fact that he was only nine-years-old at the time.

Parents John and Patsy were the primary suspects in the case for over a decade, but were finally cleared in 2008, two years after Patsy died of ovarian cancer

John says that after his daughter's death, he and Patsy did everything they could to clear son Burke from the allegations he killed his sister (John above in 2006 with his father at his mother's funeral)

Stories pointed to the fact that Burke was in the house when JonBenet was reported missing, but his parents always stood firm on the fact that he was sleeping the entire time and did not wake up until after they called police.

He was exonerated by DNA evidence in May of 1999, a little over two years after the murder.

Burke has kept a low profile for the past decade.

Private investigator Ollie Gray, who continued to investigate the murder case even after he stopped working for the Ramseys, claimed earlier this year that the child's killer was a local 26-year-old whose family owned a junkyard on the outskirts of the city - Michael Helgoth.

On February 13, 1997, Alex Hunter, who was the district attorney at the time of the murder, held a press conference where he spoke to JonBenet's unknown killer, saying; 'The list of suspect narrows. Soon there will be no one on the list but you.'

Helgoth died of an apparent suicide two days later at his home.

A few years after his death, however, Helgoth was cleared when it was revealed that none of his DNA was found under JonBenet's fingernails or in her underwear.

The Boulder, Colordado home where the family lived at the time of JonBenet's murder, which was sold for $650,000 in 1998

In 2006 - ten years after JonBenet’s death - a 41-year-old schoolteacher named John Mark Karr confessed to killing the little beauty.

He was arrested in Bangkok, Thailand, but he was never charged with the murder because his DNA did not match that found on the girl’s body.

In 2008, new DNA tests convinced the district attorney that no member of the Ramsey family should remain under suspicion, though in 2010, police sought to re-interview Burke as they continued to investigate JonBenet’s death.

The Interview will air on September 12, 13 and 14. It will premier on the 15th season of Dr. Phil's 15th daytime talk show