Mark Cuban said Donald Trump's reputation and brand are damaged.

"There's just a stigma attached to his brand now," Cuban said on CNBC's "Power Lunch."

When CNBC asked the owner of the NBA's Dallas Mavericks about the state of Trump's brand, Cuban responded that it's "done" and "over." Cuban, who has publicly endorsed Hillary Clinton, explained that Trump's brand went from being a "top five brand" to one that's "recognized by everybody for the wrong reason."

Trump has seen renewed criticism as more women have come forward with allegations that the Republican presidential nominee made sexual advances on them without their consent. NBC News has not confirmed the allegations. The allegations follow a leaked video in which the New York businessman boasts that his fame lets him "do anything" he wants to women.

Over the weekend, as some Republican lawmakers denounced Trump's comments, Cuban tweeted that "Bernie Madoff now has a better brand" than Trump.

@mcuban: Every single @realDonaldTrump hotel and golf course is toast. Done. Over. Bernie Madoff now has a better brand.

During Sunday's presidential debate, Trump brushed the incident off, calling it "locker room talk." Cuban, a billionaire, responded on Thursday saying he's "never heard that talk in a locker room, ever."

"I've never heard anybody discuss anything like that," he said shaking his head. "I've heard a lot of stupid stuff, too, but nothing like that."

The Trump campaign did not immediately respond to a request for comment.

Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank," which features Mark Cuban as a judge.