The rap icon, real name Christopher Wallace, was shot and killed in Los Angeles on 9 March, 1997, but the assailant has never been found and his murder remains unsolved.

However, his grieving mum Voletta Wallace believes Los Angeles Police Department (LAPD) officers are hiding the truth from his fans, because she is sure the person she suspects is the same name cops have come up with.

"I have a very good idea who murdered Christopher and I genuinely believe that the LAPD know exactly who did too," she tells

"They've done their investigation, but they just refuse to move forward. I don't know why they haven't arrested who was involved. It seems to me that it's one giant conspiracy, and someone is definitely being protected somewhere down the line."

Voletta has not identified who she thinks is responsible for her son's murder, but she will not rest until the case is solved.

"There's no closure for me until that murderer is behind bars and sentenced," she adds. "That may give me some closure to grab onto, but it sure won't ever bring my son back."

Thursday marked the 20th anniversary of Biggie's death and for his mother, the day is a painful reminder of how her son's life was cut short at the age of 24.

"It hurts me every single day to know what happened to Christopher and that I won't see him ever again...," she says. "Any mother who has lost a child knows exactly the devastation I feel, it's the worst pain in the world and one that I wouldn't wish upon my worst enemy. He was so young, so talented and his life was taken far too soon. It's unnecessary that Christopher lost his life at just 24. He was my baby, and I think about him every day."

"When it comes to the anniversary of the passing of his death, I don't really like to talk about it," she continues. "I know there will be a few tributes in honour of Christopher, and that's great he's still remembered, but it's very tough for me and my family."

On Thursday, Wallace's mentor Sean 'Diddy' Combs took to Instagram to pay tribute to the late rapper and encourage fans to take part in a social media movement.

"Hey, what's up everybody, today is March 9th," he said in a video clip. "Twenty years ago today we lost the greatest rapper of all time, The Notorious B.I.G. Today we're gonna celebrate his life through his music and through his legacy."

"So check this out, what I want you to do, I want you to rap your favourite Biggie verse and post it with the hashtag WeMissYouBIG, and I'm gonna chop it up, edit it up and everything and we're gonna put out something special with all the fans and friends and family involved to celebrate Notorious B.I.G.'s life," he continued. "Hashtag WeMissYouBIG, we definitely miss you."