Tupac and Diddy were said to have been part of a 'war' between top East and West Coast rappers

Says Diddy's friend and fellow rapper Biggie Smalls was killed in revenge

Police investigation never charged anyone over the 25-year-old's death

Rapper Tupac Shakur was killed in drive-by shooting in Las Vegas in 1996

A former LAPD cop claims that Grammy Award-winning artist Sean 'P Diddy' Combs was responsible for hiring a killer to shoot Tupac Shakur in a drive-by in 1996.

Both Diddy, from New York, and Tupac, in Los Angeles, had been caught up in a bitter rivalry between East and West Coast rappers, the Huffington Post reports.

Christopher Wallace, aka Biggie Smalls - a close friend of P Diddy - was shot dead six months later in a revenge killing, according to retired detective Greg Kading, who once led a special task force that investigated the shootings.

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An ex-cop claims that rapper P Diddy (center) was behind the murder of Tupac Shakur (left). Diddy's friend and fellow East-coaster Biggie Smalls (right) was then allegedly killed in revenge

Grammy Award-winning artist Sean ' P Diddy' Combs (left in 1990) was said to have hired a killer to shoot 25-year-old Tupac Shakur (right) in a drive-by in 1996

Kading claims in a new documentary that Diddy hired Crips gang member Duane Keith 'Keffe D' Davis to kill Shakur and his manager Marion Hugh 'Suge' Knight for $1million.

But on the night of the fatal shooting, on September 7, 1996, it was actually Keffe's nephew Orlando 'Baby Lane' Anderson who shot the 25-year-old rapper dead, according to the ex-cop. Suge escaped unharmed.

The documentary, Murder Rap, features a 2008 interview with Keffe where he claims to have heard Diddy declare in a room full of Crips members that he'd 'give anything for Pac and Suge Knight's heads'.

He goes on to say in the police interview that the rapper had later approached him and offered him $1million to kill the pair.

Former LAPD detective Kading says he was able to 'trap' Keffe into giving him information about Shakur's murder to avoid a harsher sentence for another crime.

Kading says that in retaliation for Tupac's murder, Suge hired rival Blood gang member Wardell 'Poochie' Fouse to kill Diddy's long-time friend Biggie Smalls for just $13,000.

Kading says that in retaliation for Tupac's death, his manager Marion Hugh 'Suge' Knight hired rival Blood gang member Wardell 'Poochie' Fouse to kill Diddy's long-time friend Biggie Smalls for just $13,000. Above: Tupac and Suge are pictured together

Suge is currently in jail awaiting trial after running over two men outside a Compton, California, burger stand in late January 2015, killing one and seriously injuring the other.

He later turned himself in to police, and his attorneys have contended that he was fleeing armed attackers when he ran over the men.

Court records show a judge has now cut his access to phone calls and non-attorney visitors at the request of a sheriff's detective investigating the case.

Kading claims that the rap mogul was behind the murder of Biggie - also known as The Notorious B.I.G. - who was one of the biggest rappers in the U.S. when he was shot dead on March 9, 1997. He was 24.

The artist was killed while leaving an awards ceremony at Peterson Automotive Museum in Los Angeles.

He got into the back of a GMC Suburban car in a three-vehicle convoy, but before the cars moved, a black Chevy SS Impala pulled up alongside his window and sprayed gunfire.

Kading was assigned to reopen the rappers' murders in 2006 after Biggie's mother Voletta Wallace sued the LAPD over claims they had covered up the real killer in her son's murder - allegedly a rogue cop.

Conspiracy theories abounded after the rappers' deaths.

Many believed the murders were part of a 'war' between top East and West Coast rappers - Diddy and Biggie were part of the East Coast, New York-based, rap scene while Shakur belonged to the West Coast, LA-based scene.

But another popular theory was that Biggie's death may have been the work of David Mack, a corrupt former LA police officer who served 14 years in jail for a $722,000 armed bank robbery in LA in 1997.

Kading (pictured) claims in a new documentary that Diddy hired Crips gang member Duane Keith 'Keffe D' Davis to kill Shakur and his manager Marion Hugh 'Suge' Knight for $1 million

Retired detective Greg Kading, who once led a special task force that investigated those two-decade-old shootings, has made the shocking claims about 2Pac's death in his documentary Murder Rap

The documentary, coming to Netflix, features footage of the rappers and testimonies from witness

Kading led the task force whose job it was to disprove the claims in the $500million wrongful death lawsuit brought against the LAPD police by Biggie's mother Voletta Wallace. His team were able to find enough evidence to clear the LAPD and all its officers of any wrongdoing, and the investigation was all but dropped (pictured are boxes of evidence)

FBI files identify the type of bullets used in the fatal shooting as Gecko 9mm, a rare metal-piercing munition.

The same bullets were later discovered at Mack's home along with shrine to Tupac - known as 2Pac on stage - and a black Chevy SS Impala - the same type of car that was used in the drive-by.

Kading led the task force whose job it was to disprove the claims in the $500million wrongful death lawsuit.

His team was able to find enough evidence to clear the LAPD and all its officers of any wrongdoing, and the investigation was all but dropped.

Then in 2009, Kading was removed from the task force during an internal affairs investigation - of which he was eventually cleared.

But in his 2011 book, Murder Rap, the retired detective claims the department dropped the case because of P Diddy's fame.

The ex-cop admits his allegations are unlikely to end anyone in court - unless he is sued.

But he hopes that by publishing his claims that it can 'hold up in the court of public opinion'.

The book has now been turned into the recently released documentary of the same name, now available on iTunes and video on demand.

P Diddy blasted claims in 2011 during an interview with LA Weekly as 'pure fiction and completely ridiculous.'

The death of Tupac, pictured with his high school friend Jada Pinkett, who went on to marry actor Will Smith, remains a mystery as no killer was ever charged

P Diddy (pictured in 1990) blasted claims in 2011 that he was somehow involved in Tupac's murder during an interview with LA Weekly as 'pure fiction and completely ridiculous'

Tupac's death also remains a mystery as no killer was ever charged.

The rapper was shot multiple times in a drive-by shooting at the intersection of Flamingo Road and Koval Lane in Las Vegas, Nevada.

He had been leaving after watching a Mike Tyson vs Bruce Sheldon boxing match on September 7, 1996, when he spotted gang member Orlando 'Baby Lane' Anderson and the pair got into a fight.

Shortly afterwards, Tupac had been on the way to a night club, standing with his head out of the car's sunroof, when another vehicle pulled up alongside him and and unknown occupants shot him, hitting him in the chest, pelvis, right hand, thigh and lung.

The shooting has passed into hip hop legend inspiring numerous theories to who was responsible for the rapper's death - including one theory that he is still alive after faking his death.