Tony Danza and Tupac Shakur. (WENN.com/handout)

Former Taxi star Tony Danza has revealed he was once Tupac Shakur's unlikely penpal when the slain rapper was incarcerated in the mid 1990s.

The actor opens up about the odd friendship in his memoirs I’d Like To Apologize For Every Teacher I Ever Had, revealing he felt he could persuade Shakur to help troubled kids turn their lives around.

Danza tells Access Hollywood, "I was trying to make a point that since he had five bullet holes in him and he was in jail and he’s the same guy that wrote Dear Mama and did all those great acting roles, I said, 'Maybe there is a better way to do this. Maybe, I know you can’t be a goodie two-shoes in your business, but maybe there is a way to inspire kids'.

"I said, 'Because you have such a great influence, responsibility comes with that'.

"He wrote me back (and said), 'Thanks for understanding me'... Then we started having this writing thing."

Danza reveals he briefly met the rapper at a film premiere shortly before Shakur was killed in 1996.