Nick Cannon wanted to address "hypocrisy" over the backlash to Kevin Hart's controversial tweets.
The 38-year-old star took to social media this week to share past tweets from female comedians such as Sarah Silverman and Amy Schumer using homophobic slurs after Hart stepped down from hosting the Oscars over previous social media posts.
He told Buzzfeed's 'AM to DM' show: "I was sticking up for my best friend... I like to point out selective outrage and hypocrisy.
"And the only reason why I pointed out some of the other people, and I could've kept going, I did extensive research... it was just showing how we all grow... I was like, 'Wow, we can invite Mel Gibson to the Oscars, but Kevin can't come?' "
The rapper's defence comes after Hart, 39, decided to quit his role as Academy Awards host just days after it was revealed he would be at the helm of the ceremony in 2019.
The 'Night School' actor had previously addressed his unacceptable social media posts in an Instagram video of himself lying on a bed.
He said: "I swear man our world is becoming beyond crazy. I'm not going to let the craziness frustrate me or anger me especially when I worked hard to get to the mental space that I am at now.
"My team calls me, 'Oh my God, Kevin, the world is upset about tweets you did years ago.' Oh my God. Guys, I'm almost 40 years old. If you don't believe that people grow, change, evolve as they get older, I don't know what to tell you. If you want to hold people in a position where they always have to justify or explain their past - then do you.
"I'm the wrong guy, man. I'm in a great place, a great mature place where all I do is spread positivity. If you're not doing that, you're not on my page."
Kevin - who recently revealed he was set to host the 2019 Academy Awards, describing the moment as "the opportunity of a lifetime" - later apologised LGBTQ community for his previous "insensitive words".
He tweeted: "I have made the choice to step down from hosting this year's Oscar's ... this is because I do not want to be a distraction on a night that should be celebrated by so many amazing talented artists. I sincerely apologize to the LGBTQ community for my insensitive words from my past. (sic)"
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