Russell Poole collapsed during a meeting with L.A. Homicide Bureau detectives on Wednesday (19Aug15) and died from a suspected heart attack.

Poole spent a year trying to bring the heavyweight rapper, real name Christopher Wallace's killer to justice.

Notorious B.i.g. was shot to death while sitting in a car in March, 1997.

The detective was among the first people to suggest the rapper's death was linked to a plot involving a corrupt LAPD detective and Los Angeles hip-hop mogul Marion 'Suge' Knight, who is currently in jail awaiting a possible murder trial in a separate incident.

According to the Los Angeles Times, Poole quit the police force in 1999 following a series of disputes over the direction of many of his investigations, including The Notorious B.I.G. murder, which remains unsolved.