AceShowbiz -

Talks are heating up that Russell Brand is romancing Holly Madison, who is best known as the former girlfriend of Playboy boss Hugh Hefner. The British actor, moreover, is said to have been making late night visits to Holly's Hollywood home earlier this week.

"Russ has been making late night visits to her home in the Hollywood Hills. He's been there three times in the past week and neighbors have heard them 'enjoying themselves' loudly", a source tells The Sun. "Russell has really hit it off with Holly. She's a big star in the U.S., which he finds really attractive. And his constant tomfoolery has her in stitches."

Romance rumors started hitting Russell Brand and Holly Madison earlier this month. They were said getting cozy at TAO in Las Vegas, where Jay-Z hosted a "fight-night party." "They were very focused on each other and definitely looked like they had a romantic interest in each other," a source said at that time, adding that both of them were "flirting with each other all night."

Despite the mounting evidence that they are dating, neither Russell nor Holly has publicly acknowledged the nature of their relationship though.