Speaking on Access Hollywood Live, Daniel said: "We worked together on the fourth ['Harry Potter'] film, but I haven’t seen him since any of the 'Twilight' movies.
"It’s lovely to see anyone from the franchise doing other things and becoming successful, but we haven’t had any contact.”
Robert starred as wizard Cedric Diggory in the fourth 'Harry Potter' movie - and Daniel, who played the titular character in the 10-year film series, admits his co-star has turned into the "most famous guy in the world" in the last three years.
He added: "He’s had to deal with a lot. [As soon as the 'Twilight' movies came out] Robert was suddenly the most famous guy in the world."
'Harry Potter and the Deathly Hallows: Part 1' and 'Harry Potter and the Deathly Hallows: Part 2' triumphed over Robert's 'The Twilight Saga: Eclipse' movie at the Teen Choice Awards earlier this month, winning a combined six accolades compared to the vampire film's three gongs.