The Welsh actress, 48, said she had found claims that the actor once performed a sex act in front of a former employee “very, very upsetting”.
Douglas spoke out to deny the allegations before they even surfaced last week, pre-empting an article that was about to be published.
He said he wanted to address the accusations levelled against him as his three children were “upset, scared and uncomfortable”.
“It was very, very upsetting. Anything like that, that is erroneous and false, would take anyone by surprise,” Zeta Jones told The Mirror.
“I’m glad that the non-story was put straight. It was a looming accusation and I am very happy that Michael did a pre-emptive move.”
She added: “This was something that supposedly happened 30-odd years ago and was unfounded, so Michael needed to make that stance.”
According to Douglas, he had been approached for comment over allegations that he “spoke raunchily” and then “blackballed” a former employee.
“I don't know where to begin. This is a complete lie, fabrication, no truth to it whatsoever,” he told Deadline.
“I don't have skeletons in my closet, or anyone else who's coming out or saying this.”