Mabuse, who has taken over from the outgoing Darcey Bussell this season, said she thought the former Dancing on Ice judge's comments were "funny", adding that she had never met Spence.
“It would be really sad if someone chose me for my colour only," she told The Sun. “I think a person of colour in any situation should be qualified to do the job. Not just because of the colour of their skin."
She added that she had expected criticism, but was surprised to receive it from someone she doesn't know.
"You’re always going to have someone attacking you in some way," she said. "But it’s weird from someone who’s never met you, I thought it was funny."
Spence had suggested that Strictly pro dancer Anton du Beke should have gotten the job instead. "They’ve got somebody of colour, which is being diverse. They like to tick every box," he told The Mirror. "I’m not saying she’s not credible, but maybe that’s why they chose her.”
A spokesperson for the BBC also responded to his claim, calling it "insulting".
"Motsi got the job because she was the best candidate. Any suggestion to the contrary is completely wrong and insulting.
Strictly Come Dancing continues Saturdays on BBC1