Jada Pinkett Smith shares unreleased Tupac poem ahead of 50th birthday. (Courtesy)

Actress Jada Pinkett Smith has showed fans a "never-before-seen" poem written by late rapper Tupac Shakur.

She celebrated what would have been the artist’s 50th birthday by "taking a walk down memory lane."

Sharing the poem on Instagram, the 49-year-old star wrote: "Tupac Amaru Shakur would have been 50 midnight tonight!

"As we prepare to celebrate his legacy… let's remember him for that which we loved most … his way with words. Here are a few you may have never heard before."

Jada believes this was the base of his track 'Lost Soulz'

To mark the momentous date, the Red Table Talk host revealed one of her most prized possessions to her Instagram followers - a hand-written poem by Tupac, who died in 1996.

In a video tribute, Jada said: "Pac wrote me many letters and many poems. And I don't think this has ever been published honestly."

The video showed an unreleased poem which was titled "Lost Soulz."

She told fans he later dropped a track called Lost Souls, but she believed he wrote this "original concept" while in prison at Rikers Island in New York.

She added: "I don't think he would have minded that I shared this with you guys."

Tupac died aged 25 after a shooting in Las Vegas in 1996.

In blue pen, Tupac wrote out the following poem: "Some say nothing gold can last forever. And 2 believe this [I] need no proof. I have witnessed all that was pure in me. And be changed by the evil men can do.

"The innocence possessed by children. Once lived inside my soul. But surviving years with criminal peers .Has turned my warm heart to cold.

"I used 2 dream and fantasize. But now I'm scared 2 sleep. Petrified, not to live or die. But to awaken and still be me. It is true that nothing gold can last.

"We will all one day see death. When the purest hearts are torn apart. LOST SOULS are all that's left. Down on my knees I beg of God. To save me from this fate. Let me live to see what was gold in me. Before it is all too late."

He signed it, "Yours, Tupac."

Jada’s mother, Adrienne Norris, commented: "This is beautiful! I believe he would have been a powerful influence in this 'state of emergency'. RIP."

Over the years, Jada has publicly shared how the loss of her childhood friend deeply affected her.

On an episode of her Facebook show, Red Table Talk, Jada confessed: "I've had a lot of loss. So many of my close friends gone.

"They didn't make it to 30. They didn't make it past 25. A lot of people talk about my relationship with Pac and figure that out. That was a huge loss I my life.