According to a former Los Angeles Police Detective, Biggie was murdered in revenge for his friend P Diddy's contract killing of Tupac.
No-one has ever been convicted with the murder of Biggie (aka The Notorious B.I.G.). However, there's been a lot of conspiracy theories.
Biggie died on the night of March 9, 1997. He was shot four times in a drive-by shooting in Los Angeles, which tragically led to his death an hour later.
Tupac Shakur died in 1996 after being gunned down in his car in Las Vegas after the Mike Tyson v Benson boxing match. He was cremated shortly afterwards and no memorial was held - and people began to believe that he hadn't really died after all.
There are a lot of conspiracy theories floating around. Why wasn't Tupac wearing a bulletproof vest as he usually did, for instance?
A few people disbelieve the coroner's report, which has allegedly got his height and weight wrong - making people think it's an autopsy of a totally different person. Did Tupac fake his own death? Check out some alleged sightings at the bottom of this article.
Anyway, Greg Kading spoke to The Sun about his bizarre theory. He said: "I don't promote what we are saying it as theory. Some people might use the word theory, because it has never been challenged in court."
Kading spent three years working on the case, and he reckons that P Diddy offered $1 million (£822,000) to Crips gang member Duane Keith 'Keffe D' Davis.
In return, he would kill Tupac and his manager, Marion Hugh 'Suge' Knight.
It's pretty confusing, but he says that Keffe D got his nephew, Orlando 'Baby Lane' Anderson, to do the shooting instead - but only managed to kill Tupac.
He reckons that as a retaliation, Knight then hired Bloods gang member Wardell 'Poochie' Fouse for a measly $13,000 (£10,686) to kill Biggie.
He told the paper that he even managed to get a confession out of Keffe D, but Poochie and Baby Lane were both dead by this point and therefore couldn't be prosecuted. He added that the Keffe D confession was useless at this point: "The American law has agreements. They can tell us everything they know about their own involvement in a crime, but we cannot use their own incriminating statements against them."
Well, as we all know, loads of people reckon Tupac's still alive.
Tupac was killed by a member of the Crip gang in 1996, but he was also attacked and shot in 1994. Although he was never officially affiliated with any gang, he was still a high-profile rapper who had feuds with others in the profession who had stronger ties to gangs. Maybe he just had enough and wanted to opt out?
Some people believe that he went into Witness Protection as he was helping the CIA take down Death Row Records.
The CIA took to Twitter in 2014 to say they didn't know where Tupac was... but they didn't say he was dead.
The plot thickens...
Tupac memorably once said: "I don't have no fear of death. My only fear is coming back reincarnated."
Well, I'm not sure about reincarnated but he certainly pops up in all the strangest places...
Let's take a trip down memory lane and revisit the best and weirdest times Tupac has been seen alive.
Tupac Taking A Selfie
This 'evidence' suggests Tupac is alive and well, and he wears a fucking cagoule.
A video was uploaded to YouTube by Tupac Legacy, and shows a
man Tupac taking a selfie.
The video has 1.3million views, with the selfie said to be taken in 2015, on a phone made in 2011.
In the video, the subtitles do say that they're not 100% sure that this is Tupac, but fuck that, it is. It's him, people, he's alive.
Multiple people have come forward to say they were involved in the faking of the rapper's death, including David Myers, a retired police officer.
"The world needs to know what I did," Mayers said. "I'm ashamed that I let a price be put on my word and I cannot die without letting the world know."
The secrets out now, mate. He's 100% alive.
Comeback album soon?
Him And Rihanna Seem To Be Best Mates
In 2011, Rihanna posted a picture on Instagram of her cuddling Tupac in Cuba. Take a look at this...
Credit: The Reporterz
Another picture of Rihanna and Tupac turned up a few years later...but experts say that it's just some Photoshop magic. Gutted.
He Likes To Stay Active In Politics
Is this a photo of Tupac wearing a luminous yellow raincoat at the 2011 Occupy demo? If Tupac had been alive during the Occupy movement, you just know the Changes singer would have been into it - he was fiercely political and critical of society.
Is this proof? Credit: YouTube
Some People Reckon This Is Him Living In Sweden
In 2015, some people claimed Tupac was alive... but not well. Suffering from schizophrenia and living in Sweden, this video of 'Tupac' is not hugely convincing. But he did get the headscarf right.
Credit: Justin Luvv
He Showed Up At The BET Awards
Apparently no longer cool with keepig a low profile, Tupac showed up to the BET (Black Entertainment Television) Awards in 2014. A bit of a weird one, as everyone there would have either recognised him or have known him personally.
Credit: 88 Beats
As they say, legends never die.
Featured Image Credit: PA Images