John Legend. Picture: Reuters

'Surviving R. Kelly' producer Dream Hampton has described John Legend as a "hero" for agreeing to be interviewed for her documentary series investigating allegations of sexual misconduct against the R&B legend.

Lifetime aired the first part of the six-episode expose on Thursday night which investigates long-standing allegations made against Kelly that he has sexually and physically abused women and teenage girls over a number of years, accusations he vehemently denies and has threatened legal action over.

As well as arranging interviews with 51-year-old Kelly's family members and numerous accusers, Dream Hampton - the executive producer of 'Surviving R. Kelly' - attempted to get several music stars and artists who had collaborated with Kelly to take part in the project but all refused except Legend and Stephanie 'Sparkle' Edwards.

Speaking to the Detroit Free Press, Hampton said: "When it comes to celebrities, It was incredibly difficult to get people who had collaborated (artistically) with Kelly to come forward. We asked Lady Gaga. We asked Erykah Badu. We asked Celine Dion. We asked Jay-Z. We asked Dave Chappelle. (They're) people who have been critical of him. That makes John Legend even more of a hero for me."

Although Legend has been commended for taking part in the documentary, the songwriter is adamant that it was an "easy decision" for him to accept the offer to speak on camera about Kelly's alleged misconduct.

Legend, 40, posted on Twitter: "To everyone telling me how courageous I am for appearing in the doc, it didn't feel risky at all. I believe these women ... Easy decision.

"We should all thank my friend @dreamhampton for her very necessary work to create #SurvivingRKelly. These survivors deserved to be lifted up and heard. I hope it gets them closer to some kind of justice. (sic)"

The series features interviews with over 50 people, including the 'All of Me' hitmaker, who comments on the cultural impact of Kelly's work, however, speaks candidly about his opinion on the numerous allegations of sexual misconduct against him.

Speaking on 'Surviving R. Kelly', Legend says: "'I Believe I Can Fly' is a powerful song and it inspired a lot of people, it was just massive." 

However, he added: "R. Kelly has brought so much pain to so many people. Time's up for R. Kelly."