Broomfield's drive-by shooting

Ace documentary film-maker Nick Broomfield has been into the lion's den on many occasions. London-born Broomfield has jousted with Margaret Thatcher, the fascist South African Eugene Terre'Blanche, Hollywood Madam Heidi Fleiss and Courtney Love. But his latest film, Biggie & Tupac is, in his own words: 'the best investigative piece I've done so far.'

Biggie & Tupac explores the maze of confusion surrounding the deaths of hip-hop legends Christopher Wallace (aka Biggie Smalls/aka The Notorious B.I.G.) and the flamboyant Tupac Shakur, both men fatally shot by unidentified assassins. Shakur was hit in his car on 8 September 1996 following a scuffle at the MGM in Las Vegas where the Mike Tyson v Bruce Sheldon fight took place. He died five days later in hospital. Wallace took his bullet at an awards party hosted by Vibe magazine at the Peterson Museum in Los Angeles on 9 March 1997.

Shakur and Wallace had been great friends who fell out during the so-called rap turf wars orchestrated by Death Row Records' then boss Marion 'Suge' Knight, who co-founded his $125 million empire with Dr. Dre, turning the likes of Shakur and Snoop Doggy Dogg into urban gangsta rap heroes. A by-product of Knight's business acumen was his reputation for allegedly intimidating and roughing up artists and employees. Remarkably, Death Row Records was an associate imprint of the Interscope corporation, owned by the Chicago department store billionaire Marshall Fields.

Broomfield's film involves compelling interviews with leading protagonists in the murder cases like ex-LAPD Detective Russell Poole. His assertion is that 'if this had been some ordinary driveway shooting by some inexperienced gang-bangers we would've solved it a long time ago. You've got to think to yourself "who could do this and get away with it?" '

If the killings were 'orchestrated' by anyone at Death Row then who actually pulled the trigger? Biggie & Tupac scours America, from Baltimore's projects to Los Angeles hood Compton, in its efforts to dig up fresh news, visiting cop-turned-bounty-hunter Kevin Hackie, Biggie's mother Voletta Wallace and two more former cops with bizarre connections to the Bloods street gang, the Mob Pirus.

While the Crips, the Pirus's mortal enemies, are a more shadowy presence, there is an extraordinary moment in the documentary where Broomfield manages to secure an interview with Knight. Wearing Bloods colours and chomping an outsize cigar in the Mule Creek Correctional facility, a kind of debriefing centre for gang members, Knight comes across as lord of all he surveys, apparently receiving stretch limousines full of visitors on a regular basis while cowed prison guards keep a respectful distance.

Without giving away the twists and turns in the denouement, Broomfield admits there were times when he feared for his safety. He and his female colleagues, producer Michelle D'Acosta and cinematographer Joan Churchill, were bombarded with calls from Death Row asking them when they were leaving America, where were they staying and what were their motives.

Once Biggie & Tupac is released in America, Broomfield feels sure he may be called back to provide the discredited LAPD with his evidence. Meanwhile the film serves several purposes: highly entertaining, it's like a contemporary slab of raw pulp fiction with real-life characters who wouldn't be out of place in a Jim Thompson novel. It also dispels some myths about Wallace and Tupac. The former was from a comfortable, middle class home while Shakur's extravagant sexuality combined his natural high camp with his constant desire to prove his machismo.

'I think it makes LA Confidential look like a teddy bears' picnic,' says Broomfield. 'There is also humour involved. Most of it to do with me, I suppose, because I'm like this bumbling white guy about to get shot if he takes one more wrong turning.'

For once the phrase, 'it's a wrap,' takes on a whole new meaning.