The 'Twilight' star was spotted driving back to his Los Angeles mansion with Keough, fuelling speculations that they are dating, reported New York Post.
"I can confirm that Riley was not photographed at all this weekend," a representative for the 24-year-old actress said.
Pattinson recently broke up with longtime on and off girlfirend Kristen Stewart.
"Riley isn't dating Rob. And I can confirm that Riley was not photographed at all this weekend," the representative added.