Nick Gordon’s Death Confession!

Bobbi Kristina Brown and Nick Gordon

The violent and volatile boyfriend at the center of the homicide probe into Bobbi Kristina Brown’s mysterious death continues to REFUSE to take a lie detector test – but has secretly given authorities a stunning confession!

The National ENQUIRER has exclusively learned her hot-tempered boyfriend, Nick Gordon – who calls himself her “husband” – broke down after she passed away on July 26, but before then told police about his role in the tragedy. “Nick made a shocking statement,” a senior law enforcement source told The ENQUIRER.

“He admitted to their abuse of drugs and booze, and also said they fought and argued.

“But Nick swore up and down that in no way did he do something that led to her death. He said, ‘I didn’t kill her!’”

Despite that, 26-year-old Nick, who has a criminal record, has yet to take a polygraph test, according to the police, who have stepped up their investigation into the demise of Whitney Houston’s daughter.

Nick believes his confession is consistent with the preliminary autopsy results, which, according to the Fulton County Medical Examiner, found “no obvious underlying cause of death,” sources close him told The ENQUIRER.

The coroner also said “no significant injuries were noted.”

Nick’s high-powered legal team is also reportedly responsible for the leaked story that suggested Bobbi Kristina likely died as a result of self-inflicted drowning on Jan. 31.

Nick, his camp insisted, found her face down in a water-filled bathtub at their Roswell, Ga., townhouse.

According to an online report, Bobbi Kristina also “got extremely drunk the night before her mom died as the two partied at the Beverly Hilton hotel. Bobbi Kristina went up to her room, drew a bath and fell asleep in the tub … intoxicated.”

On the night the “Bodyguard” star died, Bobbi Kristina was rushed to the hospital with acute alcohol poisoning, too. “Nick’s side is obviously doing some damage control here,” said the law enforcement source.

“He’s probably going to claim Bobbi Kristina often took a bath when she was high and drunk.”

In a previously recorded phone call, Nick reportedly said: “I’ll tell you the honest truth. Krissi, she was under a lot of stress and we were all doing drugs and you know, all drinking, bro.

“She just did too much man. I will officially stay away from bathtubs forever, I’ll tell you that.”

But A law enforcement source has told The ENQUIRER one of the “four working theories” regarding Bobbi Kristina’s tragedy “involves foul play at the hands of Nick Gordon.”

Police responded to reports of a fight at Bobbi Kristina’s home just eight days before the fatal incident, but when they arrived no one was home.

Authorities have also been told that the couple had a history of fighting, sources said.

As a result, detectives have considered the scenario that Nick knocked her out in an explosive confrontation, and then tried to “cover up” what he thought was her death, the insider added.

Supporting that theory, Bobbi Kristina’s grieving family has claimed he beat and abused her in the days and weeks before she lapsed into unconsciousness.

Her aunt Leolah even claimed Bobbi Kristina was murdered, but refused to finger Nick publicly.

Nick has remained silent since Bobbi Kristina’s July 26 death, though a statement released from his camp attempted to cast him in a sympathetic light.

“The passing of Bobbi Kristina is devastating to Nick and our family,” said the statement from Nick’s mother, Michelle Gordon.

Said the source: “Despite Nick’s lame confession and his team’s attempts at damage control, he’s not in the clear by any means.

“It will be up to the District Attorney to determine if Nick or anybody will be charged in the death of Whitney’s little girl.”