Oscar-winning actress Halle Berry has weighed into the race controversy surrounding this year's Academy Awards, admitting that she was "heartbroken" about the continued lack of diversity in Hollywood.

The 49-year-old star, who is the only black woman to ever win a best actress Oscar, for her portrayal of widow Leticia Musgrove in 2001's erotic drama Monsters Ball, addressed what she described as "the elephant in the room" at the 2016 Makers Conference.

"I believed that in that moment, that when I said [in my acceptance speech], 'The door tonight has been opened,' I believed that with every bone in my body that this was going to incite change because this door, this barrier, had been broken," she told the assembled press.

Berry went on to say that while she had hoped that her win would break barriers for women of colour, she was disappointed to that 15 years later, no other black woman has received similar recognition. Only three black women have been nominated for an Oscar for a leading role: Gabourey Sidibe was nominated in 2009 for Precious, Viola Davis in 2011 for The Help and 9-year-old Quvenzhané Wallis in 2012 for Beasts of the Southern Wild.

"Knowing that another woman of color has not walked through that door is heartbreaking," Berry explained. "It's heartbreaking because I thought that moment was bigger than me. It's heartbreaking to start to think maybe it wasn't bigger than me. Maybe it wasn't. And I so desperately felt like it was."

The mother-of-two Berry also co-signed Will Smith's statement that the 'lily-white' Academy Awards reflected a broader issue. "As filmmakers and as actors, we have a responsibility to tell the truth," Berry said. "And the films, I think, that are coming out of Hollywood aren't truthful. ... They're not really depicting the importance and the involvement and the participation of people of colour in our American culture."

Stars including Will Smith and his wife Jada Pinkett Smith have added her vocal fuel to the #Oscarssowhite race row after vowing to boycott this month's ceremony. However, Clueless star Stacey Dash was among the critics who have suggested that a boycott is pointless when there was more important issues at hand.

Watch Halle Berry's Oscar's speech here: